Okay, now you know the basics, before you can do chords, you need to learn how to strum.
There is no one magical way to strum, no particular finger to use, and no particular technique. Everyone uses different fingers, hand movements, and you need to figure out what works for you.
So hold your ukulele up high on or around the breast area, with the back of the right forearm on the big end of the ukulele. This will hold the ukulele to your body, though you may struggle with this for a while (get a strap if you need it). You will notice that now when you strum its not over the hole, this is normal and correct. Usually the best sound comes from strumming where the neck joins the body of the ukulele.
To strum, keep the elbow in place, and move your hand only up and down. I prefer to use my index finger on the strings, i just relax it and drag it over the strings up and down. Different fingers make different noises, and relaxing or tightening can also make a difference.
For strumming, the sound you generally want is a singular note. If you find you are hearing more individual strings, you may be pushing down to hard, try relaxing and lifting a little higher.
Place your left hand loosely over the strings at the upper end to practice your strumming technique. For now, just concentrate on a regular up and down, nothing fancy at all (we will work on that later!)
Next -> Step 4 - Chords