Is it acceptable to ask someone for help revising your paper?
It depends what you are asking them to do. 

You should definitely ask someone (maybe multiple someone's) to read your paper, give you comments about what was confusing/particularly clear/incomplete as well as suggestions on how to improve the paper. (In fact I would recommend this to anyone writing a paper at any stage, not just an undergraduate.) This might be done by your advisor if you have one, and you should thank them in the Acknowledgements section for their help (and personally too, expressing gratitude is always good!)

You should not ask someone a non-co-author to actually edit your paper and make changes to it themselves. Any actual editing should be done by you or your co-authors, otherwise plagiarism becomes a concern.