Hi Jimmy, firstly welcome to the forum and secondly welcome to the world of F1.
I'm happy to help out and answer some of your questions, there aren't many 'guides' or manuals online to assist with understanding the sport, especially the rules and regulations.
Rules Concerning the Changing of Components:
The components that wear throughout your season are:
ICE (Internal Combustion Engine) - this typically wears the fastest and is one of the components I invest in heavily when I start a season.
MGU-K - this generates electricity that is stored in the 'Energy Storage (ES)' which is used for ERS (Energy Recovery System which gives you a boost of approximately 17 km/h when used)
MGU-H - Generates heat which is again stored in the ES.
Energy Storage (ES) - Energy generated from the MGU-K and MGU-H is stored in this which is where energy collects for you to use your ERS, generating an additional 160HP.
Turbocharger (TC) - Self explanatory really.
Control Electronics (CE) - Controls all of the cars electronics, essentially the motherboard of the car.
You get so many components throughout your season, you need to use these sparingly because if you use more than what is allotted you'll receive a grid penalty. Really important - changing components after you leave the garage in Q1 incurs a grid penalty due to the 'Parc Ferme' rules. Once you've left the garage in Q1 there are only very minor changes you can make to the setup of the car.
During the game you get given an 'Event' gearbox and a 'Practice' gearbox. FIA rules stipulate that you aren't allowed to change your gearbox until it has been used across 6 races. Essentially you can change your gearbox after rounds 6, 12 and 18 without incurring a penalty. If you do change your gearbox outside of these windows i.e. before it's raced 6 events then you incur a penalty. My advice to you is to only take a component penalty when you're at a circuit with good overtaking opportunities e.g. Belgium, Spain, Monza because of their long straights and DRS zones. Don't go taking a penalty at Monaco for example as it'll just be a procession as overtaking opportunities are very few and far between. The Practice Gearbox has no limits on how many you can use. If you feel your performance is a bit poor in practice then it could potentially be your practice gearbox that is failing. Order another one, there is no penalty for this.
TIP: If you're going to order any component (ICE, MGU-K, MGU-H, ES, TB or CE during Parc Ferme or a gearbox before it's been used for 6 races then I'd potentially take a big hit and order the whole lot. It equates to about 60 grid place penalties but doesn't carry over to the next race. I normally find that I only need to do this once a season, sometimes only in the first season as over time you'll invest in reliability R&D.
Lastly it's worth running your components until you reach 60% of wear. If you can run it further then you should do because it means you're less likely to need to order new components, thus taking a penalty for the joy of it unless you're outside of Parc Ferme or of course have completed 6 races on the gearbox.
Dynamic Weather/Tyre Rules:
As you've experienced already, the game has dynamic weather and although it can be a pain in the rear, it's part of the game. When your engineer comes over the radio and tells you "There's a new strategy available on the MFD" all you have to to do is select 'R1' on the PS4 or whatever the equivalent is on the Xbox and it'll show you what tyre they suggest you go on and what lap to pit on. Normally they'll pit you that lap but be wary of your positioning. What I mean by this is at Interlagos in my first year at McLaren they boxed me onto Intermediates but it was on the same lap as my teammate and he was right in front of me so they did a double stack - a method of pitting two cars consecutively which is an art form when it works but an absolute car crash when it doesn't. I lost quite a few places because of this because the pit box couldn't release Lando into the pitlane due to incoming traffic.
There are 6 different compounds in F1:
Hard - White striped tyre that is the most durable compound but also the slowest. The hard tyre is normally a tyre to practice on for quite a few laps as it stands up really well but I'd avoid using it in a race unless you have to pit early doors because of a shunt or puncture allowing you to go longer in the race, thus allowing you to make time up from the unscheduled pit stop.
Medium - Yellow striped tyre that is in the 'Goldilocks Zone' for performance and durability. It's the medium speed and durability.
Soft - Red striped tyre that is the fastest but wears the quickest. Bare in mind, hot and fast tracks such as Bahrain, Monza and Abu Dhabi as an example will chew these up quicker because the more heat in the tyre, the quicker it wears.
Intermediate - Green striped tyre that is used when it's raining but there is a clear racing line or dry area on the track, these tyres have an actual tread on them and work similarly to road tyres by scooping up the surface water and passing it behind the tyre, thus creating grip.
Wet - Blue striped tyre that is used when it's properly bucketing it down, when the track has puddles on it and the intermediates no longer cut it.
You get given a finite amount of tyres to use across the weekend, normally this equates to:
Hard - 2 (1 practice, 1 qualifying/race)
Medium - 4 (2 practice, 2 qualifying/race)
Soft - 8 (3 practice, 5 qualifying/race)
Wet weather tyres - you get an allocation of Intermediate and Wet tyres in a wet race, I'm unsure on the quantities but it's an ample amount.
One thing that's massively important more so these days is set-ups. What I mean by this is car set-ups, ensuring that you've got the right set up for your aerodynamics, tyres, suspension etc. There are two YouTuber's that I follow who publish their setups and do a 'hotlap' to show you where your braking points may be and tips of tackling each individual circuit. As @kenuf mentioned, Tom97 (https://www.youtube.com/channel/UC-jYK2AdVmH8LNcjTI_lI6g) is a great user to obtain set-ups from and also two more I use is Jaaames (https://www.youtube.com/channel/UC0Ene38yf-Y6movLKSvc0Iw) and TRL Limitless (https://www.youtube.com/user/JDisMoNsTeR). These guys are all e-racers and are really good. It's worth noting, experiment with the setups because they aren't all going to work for you. Each individual setup has pros and cons so play around with it.
If you've got any more question's please feel free to drop me an IM on here if you can or drop me some contact details such as e-mail and I'll happily assist.