BIOS Malware and Infected Router

hello, pls can someone with experience tell me what to exactly do .. i'm a bit scared cause i am not sure..

long time ago my computer was full of viruses.. ofcourse i reformatted like 8 times but still,i also had an android who still got full of viruses ( i know i was stupid) and then factory reset it.. i think this formats it and delete viruses i guess right?anyways

i was wondering if my android is infected can it infect the router and do some computer worms and infect everything? i mean only from an android??

i plugged in again my old computer which was full of viruses may it be bios hacked? and if so.. how can i detect this and remove it..

if my router is infected how can i detect and remove...

Pls i need help as soon as possible i am really worried cause i have some important stuff..