A Raspberry Pi is the perfect playground to get started with self-hosting. It is cheap and barely takes up any physical space.
Pi-Hole and bitwarden are simple enough applications that you can host both of them on a pi. Plus there are plenty of guides available online to guide you thru the process if you do get stuck.
I got started with self-hosting pi-hole on a raspberry pi myself.
Yes but only a Raspberry Pi 4. The improvement compared to 3 is so big, that it's not worth getting a 3.
And it's nearly impossible to get any of them. I've been trying to buy another 4 with 8 GB for over a year now, but am not willing to go beyond 80 € for just the board.
Pi-Hole and bitwarden are simple enough applications that you can host both of them on a pi. Plus there are plenty of guides available online to guide you thru the process if you do get stuck.
I got started with self-hosting pi-hole on a raspberry pi myself.