I can offer you various editing approaches:

• Good old Microsoft Word with Tracked Changes — The majority of my clients prefer this [example]
• Annotated Adobe pdf — Great for a final proofread of something you’ve already formatted: a presentation, flyer etc.
  
• Marked-up Adobe pdf — This is one for the hard-core professionals: BSI proofreading markup (to BS 5261C: 2005)
  
• LaTeX — For Maths / Physics / Engineering / Computer Science papers*

*Please note that I am not aware of a way of ‘tracking changes’ with pure LaTeX. You get back an edited LaTex source file and generated pdf, either of which you can compare with the original with file comparison tools. However, if you use the Overleaf service, they offer full change tracking. I haev an account on Overleaf and can help you upload your file – there is a small subscription charge.