I don’t have the game in English, but basically go in “Character Configuration”, “Hotbars” and set your hotbars there, you’re gonna need 3 for combat at the very least, sometimes 3 and a part of a fourth.
Set up there hotbars you will share between jobs (the ones on which shortcuts never change when you switch jobs), and hotbars that won’t be shared, set up at least 4 for those ones.
Set there their shape to your liking, as well as a bunch of other useful straightforward options.
Then for every combat jobs, make sure you put on your 3-4 unshared hotbars every single skills from the “skills” menu, make sure you put there the class/job skills, as well as the “Role” ones.
And of course after that, go into the keybind menu, and make sure there’s a keybind for each slot of the 4 unshared hotbars, and make sure those keybinds are made of only one key, not a combination of keys, as this could cause potential problems, and would also be slower.