There are soprano, concert, tenor and baritone ukuleles. Soprano being the smallest and having the brightest sound while baritone are the largest and warmer/lower sound. The soprano is the most popular and it’s sound is the one you will usually recognise the most. The baritone one has a sound that is almost a guitar. The concert and tenor sits in the middle. Mine is a Tenor uke. There is no wrong choice. Best would be to go to a store that sells both and give them a try and see which sound you prefer.

Here is the same song played on soprano and tenor ukuleles:
Soprano. Notice how you can’t see my face in this one. It was one of my first YouTube video and I was like you not comfortable showing myself on camera.

Tenor