First orgasm

I have never had sex or been fingered or eaten out but I play with myself all the time. I used to play with a handheld back massager down there but it just broke so I ordered a new one. I always get a throbbing sensation when I keep it in the right spot. Is this an orgasm? How will I know if I reach an orgasm? How can I try to achieve it just fingering myself? Please help!