Best man

[Filterphobia]

Should the best man spend the night before the wedding with the groom and be there with him overnight so he’s there first thing in the morning before the wedding or is it acceptable to stay separately and then go to the grooms on the morning of the wedding, say 3 hours before, and then get ready together?

Do whatever suits the groom, and the best man.

I would say it is most typical to go there in the morning, but will depend on things like where the best man lives (ie, is he local or is he staying the weekend in a hotel / at the venue anyway.).

Also what time the wedding is
Also if the best man has his own family
Or If the best man has travelled to the wedding with a partner and if they would then be on their own
and probably 101 other factors.

There is no 'rule'

No rule. Our Best Man lives nearby and has 2 small kids at home so wouldn't expect him to stay overnight, he'll just meet DP in the morning.