Please look at the advice and guidance on the careers website about CVs and cover letters.  Once you have done this and made any appropriate changes you can use the CV360 software to get electronic feedback:

https://www.ed.ac.uk/careers/application-interview-advice/cvs
 
You can also then seek CV feedback in person, either at a drop is session or at a booked appointment:

Maths careers drop-in (JCMB, Outside Magnet Café)  Mondays, 12.30-14.30 with Matt Vickers – just turn up and wait;
Booked careers appointment (Murchison House) Availability and bookings shown on MyCareerHub, 48 hours in advance.

https://www.ed.ac.uk/careers/about-us/what-we-do/iag-services/appointments