I had COVID (asymptomatic) in the fall.
My shot was scheduled on a Saturday and the night before had a couple beers, was up late watching a movie with the family, stuff like that. Got the shot Saturday afternoon and felt fine until Sunday afternoon then it kicked my ass. Joints felt like I was 90, extreme fatigue, etc. - but no fever.
For my second shot I wanted to be smarter about it. Went to bed early the night before, no alcohol, slept 9 hours and I was ready. Felt good all Saturday and Sunday morning was out and about. About 3:00 Sunday afternoon spiked a fever, had shivers, bad joint pain and felt really awful for about 4 hours then it got a little better to just feeling not great.
So my experience is its going to do what its going to do so I wouldn't worry about prepping for it. And hopefully it doesn't impact you at all. My mom and wife had no side effects which in turn means they think I was exaggerating.
The good news is Monday morning both times I felt totally normal with no lingering effects.