Starting off, I'd learn these chords:

C major, A major & minor, G major, E major & minor, and D major & minor.

They're a good starting place, as many a song out there uses some combination of them.

Practice changing between them! After awhile, get a metronome app, practice changing between chords in time with a basic strumming pattern of just downstrokes. Four of them per chord. Then move onto some uppy downy stuff. As others have said here there's many great free online lessons on YouTube and such. Covering all of what I'm saying and more in much more detail.

Other things off the top of my head, learn how to hold a pick (it's gonna feel real weird for awhile), I can't explain well over this but it's an easy search on Google. Oh and how to hold your guitar, might sound silly but it's important. There's videos on that too.

Have fun and good luck!