There are several easy ways to start kino escalation. If you are really shy you can start by make contact with a part of your body against one of hers (like elbow-elbow) but you have to make it look like you don't do it on purpose. You can also lean to her and say "i like your pafume, what is it?" or something like that.
Afterwards you should try to reach her hand. You can use an excuse like "wow, you look like you have soft hands! How much do you care about them??" (try to make it sound funny. It will work 90% of the time). After having a hand you should try to reach her arms and then her hips. To do this I suggest to behave like an italian: you gesticulate really much and do physical contact all the time (i'm italian, so i know what I'm saying

) and you push a little more when you feel she's confortable with your touch. After the hips I usually lean in for the kiss directly, but if i don't, i try to reach her back and scratch it a bit
softly. Afterwards you try to get the back of her head and pull
gently her hair. At that point you should have built enough confort to lean in for the kiss. Then you touch ass, boobs and vagina.
Briefly, that's it. If she stops you, you
go back one step, wait a bit and then
try again. Either she'll let you go on, or she will go away (99% is the first case).
Don't be afraid to touch them. Touch their body with as much attention as you touch yours.
Hope that i've helped

Good luck!