I don't know how to make myself wet before i start self-pleasuring

After having a bath/shower while your still naked start by using your imagination and fantasizing it's someone else rubbing and massaging your breasts and running there hand down your body and between your legs and just over your labia not between and you should get turned on and wet

Start by getting naked and laying on ur bed play with ur tits slowly getting the nubs to grow and i would say watching some porn to it really helps. Then u should start to rub ur vaginas but don't enter it, and playing with ur clit will also help.

You should avoid using porn as a stimulant to help arousal or during masturbation as it can lead to problems later on when trying to get aroused during intercourse and also getting to orgasm without it.
The best way to is to just lay back think of a hot guy being with you and use the power of your imagination.