Experienced people: and questions?

i am 18 years old and i would like to know a few things. i would really like to have with my boyfriend (we're both virgins) and i would like to know how to go about this a very safe way. i have given to a previous boyfriend when i was 16 years old. I would like to know is it safe for me to have oral with my current boyfriend? and i understand that there is no 100% guarantee on preventing pregnancy, but how effective are condoms? any condom bran reccomendations? i'm trying to be safe, and avoid getting STDs etc. It is to my understanding that certain STDs such as chlamydia and syphilis can be spread from oral, but if im healthy and only had oral with one other guy, and my boyfriend never had oral, we should be fine, right? thanks in advance