If you have installed any nsp,xci,nsz,xcz (even homebrew nsp like tinfoil) it "dirties" the nand. What alot of people mean by dirty nand is installing stuff thats not legitimately bought or installed homebrews (when I say install, I mean putting it on the home screen. Not putting the nro files in the switch folder)
So since you have installed stuff thats not from eshop, it is considered "dirty". If you try to connect to nintendo servers at this point, you will be flagged for a ban.
Best course of actions now is make an emmunand/emummc (both mean same thing). Restore a clean nand backup (a nand backup that was created before you installed tinfoil, etc,) thats your best course of action. Also if you're gonna use tinfoil for the "shops" 90dns bogs down your download speed. Install incognito_rcm/atmosphere incognito on ur emunand.
