New to selfhost. I have some questions

Im so bored and i want to turn my moms old laptop to a selfhost server even i dont need it. I tried casaos and popular apps like nextcloud but i have few questions can someone help me about it.

- Should i go for casaos or there another docker things (i dont know whatever it called) good and free?

-Sound is really important in family house. Laptop is already quiet if you dont load it too much. Does these apps make too much load for my sh.tbox?

-Which apps should i use?

Laptop:

Amd A6 something

4 GB Ram

120GB M2

No graphics card/APU

HP 15 rb009 (if i dont remember wrong)

Note: im new in reddit and this is my first post. Forgive me if i made something wrong.