If you wanna practice and get better, don't just rack up balls and start shooting. Set up shots you normally see in a game (ball stuck on a rail, cut shots, etc) and practice that.
But first things first, make sure your shot is straight. Take the cue ball aim at the rail across from you and try to hit the rail and have the cue ball come straight back to your cue. If you can do that then your shot is straight and you can move on to make shots. You should be able to do this consistantly.
Pick up a book if you can. All the information you'll ever need can be found in a couple books. After you have the info, PRACTICE PRACTICE PRACTICE.