Here are few tips on how to make girls like you:

Be Likable
In order to make girls like you, you have to like yourself first. Make yourself likable. This doesn't mean that you have to be good looking, but you have to be looking good. In order to look good you must look clean. Learn to shave, have a good hygiene, and dress well. If you're not comfortable with what you wear, then buy yourself some neat clothes. Go to the mall and look for some clothes that make you feel good. That way you can build more confidence and have more chance to be liked by your date. Take some time and effort to make a good appearance because if you do you'll be more appreciated by your date.

Be Confident
Women love confident men (Even those that are really beautiful.) They find it very sexy even though you're not that good looking. Believe me. You don't have to be handsome to get those girls like you. Just be confident about yourself but don't be overconfident. Avoid being a jerk and don't brag about yourself. One surefire technique in being confident is not to need women so much.

Overcome That Weakness
If you're scared about talking to people (or strangers) then you have to start practicing how to socialize. Practice talking to other strangers. An old man or a fat lady can be easy to start with. Practice makes perfect so learn to practice more to overcome that weakness.