Newbie in San Diego (another one)

Hi all! So I just recently got an internship in San Diego, I am from Ohio. Ever since I was little I have desperately wanted to surf, so I finally have an opportunity! I have used a foam board once in North Carolina and gotten up, but I know that is a totally different ballpark. I am looking at buying a board on Craigslist. I want to get a board that is affordable (I am a broke college student) but that will allow me to progress throughout the summer. I will be here for 3 months and aim to practice surfing at least once a week, 2-3 times if possible. East coast vacations I would spend hours upon hours in the ocean and had to be dragged out and I am a very stick to it person so I don't believe I am just going to try it then quit it. I play college soccer but have been working on strengthening upper body. Any tips on good cheap boards for a beginner, again allowing for progression. Also any info on great ways to learn to surf on my own without having to pay a lot of money for lessons, I might shell it out for at least one. With lessons and a board the expenses can add up really fast (thankfully I already have access to a wetsuit). I am hoping if I get a board that I can resell it later before I leave (as I can't take it back on the plane with me). I am a female 140 lbs and 5'6". Also, I have been reading up on surfing etiquette and other beginner advice elsewhere. Oh yes and I'm located in Carmel Valley so any good spots near that area so North of the city. Thanks for all your advice in advance!