would an antenna booster help my AM signal on my radio?
1
lan
If it's designed for AM radio then yes, otherwise, probably not, no.
Many TV boosters block anything outside their expected frequency band to reduce interference.
2

alanr
For MW something like this would be much better as it boosts the signal, increases directivity and selectivity making it easier to sort out the signal you want from all the other signals
They are VERY effective
Pro tip