Take an existing latex document and make it clean

Hello everyone! I am currently doing an internship report with Latex. Both the code and the pdf are fine, but there is still a lot of work to make the job well organized and clean. I would love to have someone with a lot of latex experience to make this job very clean and professional. Looking forward to seeing you!

P.S. Be aware that the internship report is written in French. I don't think it really matter here.