What step r u getting stuck at? Let me explain - as in many other things, getting into a relationship w/ a woman consists of steps, the actual "girlfriending" being the last step.
Step 1: meeting her
step 2: flirt and get her attracted to you enough for:
Step 3: close - which means either get her to go on a planned meeting with you then and there, tonight, or if no better option secure her phone #
Step 4: The date, or dates if required. Create more attraction, initiate physical contact: touching, then kissing, fondling, get her in heat.
Step 5: close the deal: willingly maneuver her into a situation where the two of you wil enjoy hot steaming sex.
Step 6 and beyond: decide whether you would like to maintain contact with this girl again, possibly leading to a relationship.
Each step requires a different set of capabilities/set of mind, and each step requires practice and more than a few strike-outs when you are starting out. So again, which step are you in now?
For example, if you are at step 1 - meeting here, this initially consists of you creating loads of situations for u to meet hot chicks, as suggested by others here: gym, hobbies (especially those with primarily women for example ballroom dancing if you are inclined to it or yoga or volunteering at pet shelters ...). Once you have the opportunities, you need to concentrate on the next sub-step which is the approach and so on.
Your question was very general hope I have helped you.