I play the english version, you can download it here (or here , if iOS). About the differences, the EN version is about 2 years behind the JP one, however, it is following the JP schedule pretty faithfully (as far as I know), so plenty of people manage their resources based on that.
FGO actually have it's own wikia as well, although it's mainly (if not completely) for the JP version, but even so it is still pretty useful. For now I only have the wikia link, but I do know that there are other guides... Are you familiar with 4chan?
Humu... well, it is indeed pretty F2P friendly, no doubt about that, since you can pass pretty² much everything with just 3★ Servants (there are exceptions, of course), however, the gacha can be pretty³ brutal, so if you want a particular 4★ or 5★ Servant, the RNG might not help you (which makes me wish for every game with a gacha system to be like Aigis and have a guaranteed 4★ and 5★ every X pulls...)... but obtaining Summoning Tickets and Saint Quartz (the Sacred Crystal equivalent) isn't very hard, and again, we can predict when which Servants will have rate ups, so deciding who you want and prepare for them may prove effective.
Don't worry about that, it's always good to see people interested in games you like. Actually, I'm the one who should be apologising, for rambling in my explanation, but I hope it's understandable.
And about the 4chan, you don't really need to go there, but I heard that there's a Fate thread on /a/ and there might have links of other guides (but if you like Yuri, there's a thread on /u/ as well, if anything, you might at least get some tips).
PS: If you want, post your ID here later and I'll add you.
I made a little search already and found minor info in 4chan as i'm not used to it, but i found a lot of helpfull info in the FGO reddit and although i got some trouble while installing the game, now i can play it well and tomorrow when i level up a bit i will uptade this.
Just wanted to give you a insight of my progress after playing for a month and again thanks for all the help.
I luckily got Raikou from the gacha in the middle of the Onigashina event after pulling before i sleep, and now thanks to her i got almost everything i wanted from the event shop :)))
I'm really happy with my progress, happy with my first ssr pull and from the servants i could ascend, it's a similar feeling from having your units in aigis aw and saw, it's really cool to see your characters getting strong and right now i got addicted to FGO xD.
So sorry for this happy pull text out of nowhere but thanks again for the help in starting, and i'm looking foward in someday being able to help you with my units. ^-^