I am in someones house whos ip got banned will i get banned

i am having to live here because of family reasons but i just dont want my account to get banned man.

I got a little scared when I saw the first four words of the title.

Nope
ip addresses are related to your devices
They do give an estimate about your location but bans are device-based

Well, if you are behind a router which uses NAT (Network address translation, common for the home routers) with a banned guy, you indeed in trouble. But I don't think they will ban you, that will be too cruel, only will not allow you to create a new account. But this is only what I think, I did not experiment.

Nope lichess allows to create a new account even if you used computer assistance you cant use the cheater account
This is not like chesscom
So don't worry

@Koo8384 This is not true. Don't confuse local IP's and external IP's. If you check your external IP, for example using service myexternalip.com/ you most probably will find that all your home devices have the same external IP.

#1 Did you cheat? If so you'll probably get banned.

If you are banned in error, try lichess.org/contact#help-root