[@Shusuke]That's where I can hopefully put your mind to ease. The character sheet is absolutely massive, and since that is the one thing I require to base a lot of the encounters and story on, I require my players do put in the work once, and then only use it as a reference.

But as such, the character sheet should have everything you need to start, without having to read D&D material. The only things I use from FR is the world itself(which I do my best to detail to everyone regardless of knowledge), the magic system(which I also use with liberal explanation) and items(because they're fun, and again, explained if you don't know about them). The rest is up to interpretation. If your character sheet doesn't have an iota of D&D references beyond the basics provided, that's fine!

Armour and weapon stats can be nailed down in the OOC, so this is certainly something I can help you with. You're not alone in this! Ask as many questions as you want, it's what I'm here for. Abilities, skills and spells are three different categories of what your character can do, and break down into some trivial differences:

Skills are things you have to practice with to get better.

Abilities are activatable or sustained things you can do, not necessarily related to your class, race or history. Something you learned to do as a kid, something not necessarily related to your class, a remnant of a different profession, all that kind of fun stuff. 

A Drow Elf for example, has the innate ability to cast a Globe of Darkness. It doesn't matter what class/length/height/stats the drow is, but because he is of that race, he gains that ability because all drow do.

Spells are specifically for spellcasters, and function much the same as abilities otherwise.

My advice is, make sure you have the long term time to put into this RP(months and months), and make a character sheet. Post it in the OOC, I'll look at it, indicate what needs fixing, and repeat the process until your sheet adheres to my standards. Looks scary, isn't.

So a character can be a fighter and not have any spells, but have the maximum number of abilities, and vice versa for a spellcaster.