First of all, welcome to the forum, im new to TB myself.. but here is some pointers:
You will need a lot of patience to start making your bass lines and playing with the bass, specially if you played any instrument before the bass.
First: exercise, exercise, exercise, exercise, exercise and then exercise some more. There are great exercises on the web (if know hoe to read a tablature), try
www.ultimate-guitar.com and search for bass exercise in the lessons part.
Second: Try to play with all your 4 fingers of your left hand (yes, pinky too!!) slides sound cool, i know but you need to work your pinky finger because if you do, you won't be stuck at a later level when you trying to develop some speed
Three: always, i mean ALWAYS use your right hand fingers instead of a pick. at first you will find it tedious and boring because you will miss the strings a lot and your fingers forearm muscles will hurt, but thats just a matter of keep trying and practice
But the most important thing you need to do is, regardless of the exercises and the praticing and so on, you need to like, or even love what you are doing, without passion there is no music
well that being said, I wish you good luck and my sour fingers
rock on
P.S: sorry for my english.. it's not my main language :P