Sounds like a nylon string acoustic. The lowest-pitched strings are wound with wire, but are still nylon on the inside.

Start off with some open chords - C, D, Dm and G, Em (all the chords in the keys of C, G and most in A are open chords, so you'll find these three keys the easiest to play in). Do ask your friends for some pointers, and check out videos on youtube (eg search "beginner guitar").

Google Ricci Adams' Music Theory and do some of the lessons. They get quite hard quite quickly, so don't stress if you don't understand it all (esp the Neopolitan stuff).
The lessons "The Basics" will be good for you, although if you're reading tab it won't be so relevant. Scales and Key Signatures are really important, as are Intervals, Chords, Diatonic Chords (a bit hard towards the end but worth a look) and Chord Progressions would all be really beneficial for you. But you don't have to learn it all at once!!

Also the fretboard identification exercise will help you.

HTH - have fun!! xoxo