I want to change the icon size of debuffs (like immolate on the screen), above nameplates and font of character's name/health/percentage on player frame
Is there also a chance to change weak auras so it works a bit different ? I would like to put them vertically - somewhere around the middle of the screen and enlarge then a bit so i can always see my debuffs
I don't think it really matters how I say this, you will probably take offense. It is quite clear you are either new to elvui or don't bother looking through the elvui config before asking questions. All of the above things you are wanting to do could easily be found within a couple of minutes if you just take a moment to look in the config. Also, it is possible to do what you want with weakauras as well if you just take a moment to look over the options etc.
Well, what the above poster just said, those things you want to do is real easy if you only looked at the options you have.
But i can spoonfeed you some info to get you on your way.
Go into elvui config and for "icon size of debuffs" you goto frames, target, aurabars or debuffs and change the settings there to your liking.
Nameplates, goto.... nameplates! and fiddle with the settings there to your liking.
Font you goto frames then select player from the dropdown menu and select to font you want.
Weak auras question is really really easy, weak auras is just drag´n´drop everything, so i dont really get why you´re asking that. I must be misunderstanding something?
Otherwise just select the aura you wish to move or change size on, drag it to the correct position, drag one edge of the aura to enlarge it.
Hopefully got it all right, writing from memory as i dont have a wow installed on this comp.