Aha wait I just realized: I got 162V and 170Q, not that it makes any difference though tbh xd
The GPA was all of my 3rd and 4th year credits at the time since they look at your last 5.0 senior credits (3rd and 4th year courses). If they included 1st and 2nd year courses, it probably would've been higher. Just a note, if you don't have enough senior credits to fill up the 5.0 they'll take it from a 1st or 2nd year course (provided you only have to fill like 1 or 2).
I think NovaTerra gave pretty good advice about the letter of intent. Address any shortcomings in your academic life and how you tackled them, talk about key experiences in your CV (preferably oriented towards epi or stats, determinants of health, data analysis, etc.).
For my references, I used my undergrad research project supervisor and a prof who's taught 3 of my senior classes (class sizes were small so we've interacted quite a bit).
Haha I don't have a linkedin unfortunately ? Although, it probably wouldn't be a bad idea to make one soon.