If you're a kid in this position, wondering whether it's dangerous to have sex, the answer is yes, it's one of the most dangerous things you can possibly do. Wasn't that long ago that having sex could put you in an early grave with an uncurable disease.
So just add "false accusation of rape" to the ever growing list of things that can happen to you if you're not careful with your jubbly bits.
Get everything in order before you start having sex. If you're in school, make sure your grades are decent, you know how to wrap it, line up someone who you know is interested and already have a friendly rapport with.
To go about it in any other way at all is to invite grave danger. It's always been this way, there has been no point in at least the last 1000 years, probably even longer that sex couldn't royally ruin your life.