Do I need a vpn for home use

Assuming that you are securely connecting to your Bank using SSL, using either a trusted web-browser (https://..) or their dedicated App (which you hope is similarly secured) - and you “trust” your ISP - then use of a VPN will add no tangible security benefit.

If connecting over an “untrusted” network (such as a public hotspot) then use of VPN via a reputable “paid” VPN provider would be advisable.

No.

The answer to that question depends entirely upon (a) what you’re trying to protect - and (b) whether you need to hide any of your activity from your ISP.

You are most welcome.