Multilogin setup help

Hello folks, I’m looking for an affordable multi login app to set up a new BM on my PC, which is affiliated with past disabled accounts. If anyone has recommendations that’d be great.

I am also wondering if there is a proper way to set things up.

For my scenario, I am using a family member's FB account to set up a new BM. The thing is this person only uses it on their phone and tablet that is connected to the same WiFi that I am on. Will I need a proxy? How should I go about it? Thanks for reading!