Get a decent ukulele.
This is the most important one of all when you are serious about wanting to learn how to play the ukulele. There are a few good ukuleles in the $100 range, but you can almost be sure that a ukulele under $50 is not that good. The main issue you will have is that it won’t be able to stay in tune.
First thing's first, the basics.
When looking on YouTube and other websites you will quickly learn that amazing things can be done with the ukulele, but like every skill in life you’ll need to learn the basics first. Don’t try to play some big fancy tab when you are just starting out, learn your basic chords instead.
Play as slowly as you can.
When you know your basic chords and can do some basic strumming you can eventually start to change between chords. Practice this a lot and with many different chords and at first do it as slow as you can so that you can’t possibly make a mistake.
Record yourself playing and listen back to it.
It’s difficult to play and listen to yourself at the same time. Quite often just noticing what you’re doing wrong is enough to fix the problem.
Besides learning chord shapes, learning how to strum, learn how to quickly change chords, etc… you’ll also need to do some finger exercises. This will help to gradually build up calluses (= toughened area of skin which has become relatively thick and hard in response to repeated friction or pressure)