Help please

Hi, well ive been with my girlfriend for nearly 5years, and started to have sex a little over 2 years ago, and just recently trying oral sex and I can get her to come but I was wondering if its safe to swallow ect and can someone tell me what it tastes like so I'm not so supprised when I do?
plus I need some tecniques in oral sex, I tend to suck on her clit but she just cant handle it! shes always trying to push me away ect when it gets to much, what else can I do? can I put my full tongue inside her vagina, what kind of things can I do so she gets the ultimate orgasm without it beeing to much without her budging?.
im 16, shes 17 in 3 weeks

Pane oma keel talle sügavale putsi ja oma ninaga hõõru ta kliitorit. Kui ta orgasmi saab siis tuleb suure kisaga ja kusega.

You're not doing anything wrong.
Every girl is different and some things that one girl may like, another girl would hate. The key to successful sex is communication. Just be open and ask her what she likes. You'll know when something you do is too much for her!!!
Also FYI every girl tastes different!