It's easy, just make sure you're consistent with practise, even if it's only fifteen minutes per day.
I've got a banjo ukulele that I taught myself. I was lucky though as my girl learnt the uke at school and still had her books.
After a few weeks she stuck her head round the door and said, "have you just been playing Waltzing Mathilda and King of The Swingers?" so I must've been doing something right.
I've not played for about six months though, so now I'd struggle to put a run of chords together.