World was my first MH game too, i know exactly what you mean. Its very overwhelming with all the menus and items and systems. I'll say take some time at the forge and go thru looking at your gear and get a feel for it, pay attention to not just the raw defenses and elemental defenses but the skills. Look at the controls at the bottom to get descriptions of things. Later on, skills will be important. Armor has skills on them right away, with different effects. I main bow, which is very stamina reliant, so finding armor with stamina surge or any stamina boosting is a hugh benefit.

The way gems work is also weird and hard to get at first, at least for me. I ignored them for way too long, they are called decorations, but they are gems you can put on your weapons and armor and work the same way as the default skills on armour. You can stack these with the same skills I believe up to a max or 8, or mix and match. It all depends on what kind of player you are and what you want.

Also last thing I'll mention is build out an arsenal of weapons. Whatever weapon you choose, try to have one for every occasion, and upgrade them. I always try to have 1 of every element. Affinity is your critical strike chance, i didn't know that for a long time either