أحسن الله إليكم Ustaadh, when a Muslim revert learns how to pray, should they follow a certain madhab or watch a tutorial such as Shaykh Aziz Bin Farhan’s video on how to pray?

Yes, you can. It is especially beneficial when you watch a video from one of the trustworthy mashayikh, such as Sheikh Aziz Farhan (may Allah preserve him). It is very helpful for you to watch and learn from what he does.