Ok, several issues here. First, proclaiming your undying love for someone is generally not a good move. You just need to be together and let the bond grow. The relationship evolves from there.
As far as the kiss, the way to start is with gradually increased touching. Knuckle bumps turn into light shoulder punches, etc. gradually build the physical contact. If you touch her and she tenses up, then back off and try later. Work up to putting your arm around her if you're sitting or holding her if you're standing. Then just lean your head down while parting your lips slightly. You'll know what she wants you to do.
The key here is to read the signals. As you escalate the level of contact, you'll know if she's comfortable with you going further. Just observe her body language. If you put your arm around her shoulder and she relaxes into you, then she's comfortable with that level of contact. If she tenses and pulls away, she's not ready. Be sure not to move faster than she's comfortable with.