Hello Francis!
Welcome to the community and feel free to ask anything at all. I can't help much - I'm one of the guys that
needs help lol but I can say this place is extremely friendly, helpful and outgoing.
My personal advice is once you get SH5 up and running, play Vanilla (the basic game) a few days until you get comfortable, and familiar with its many deficiencies. Then, download the incredible "Wolves of Steel" mod, which turns the game into simply one of the most outstanding sub sims ever built.

It takes a bit of careful work, but the install guide (which I personally ignored the first time to my detriment) gives a step-by-step procedure for installing. I can't recommend it highly enough.
Cheers! And welcome!