I've hand-picked a lot of essential and great things for bassists and musicians. Shopping through these links benefits StudyBass and costs you nothing extra. I don't recommend anything that's not of great benefit to students, and I am not paid to promote any specific products. These suggestions are based on my own personal experience and that of hundreds of students over the years.
To get you started, I have a few models of basses I suggest. There are so many great basses to choose between. I try to keep it simple for you. As long as your bass is playable, it's mostly up to practice to sound good. Get a bass--any bass--and start practicing!
Next, it's essential you have an amp. Without one you can't hear the mistakes you might be committing. If you do that for too long, you will develop some terrible sounding habits. Get an amp so you can hear yourself.