I think you could do it. The important thing is to look up tutorials, take your time, and practice new techniques if possible. Being patient and doing your research will minimize the amount of re-work you may need to do.
There are plenty of tutorials on Sailor Senshi fukus, and tons of tutorials on how to make large props with PVC, expanding foam, worbla, etc.
Do you have specific questions on the parts of the costume? Also, do you have access to a sewing machine?