I really enjoyed french alevel. i would say you have to be willing to put in the work consistently as its not something you can learn overnight. so if you are a crammer, i wouldnt recommend it. do you think you will be motivated enough to put in the work that is needed? do you have a passion for french? you say you're doing history, so there's no doubt you'll enjoy the historical modules, but is grammar, literature, movie studies etc something you would be interested in?
from what i have seen, for people taking french a level, you either absolutely love it or absolutely hate it. you either love it, because you find it incredibly interesting and are motivated to put in regular work, or you hate it because of the amount of maintenance it requires.