Just go slow, communicate, and do what you feel comfortable with.

Definitely go slow. Start with the kissing, that's always the easiest, even though that can be pretty scary, too.

Make sure that if either of you get uncomfortable you say so, and that you make sure that you know what the other wants and vice versa. Dim the lights, turn on a movie or some music, haha, set the mood.

Before my girlfriend and I started dating, we started to make out on my couch, and before I knew it, she had me on my back on the couch.

Just start with the kissing and cuddling and go from there with what feels natural and comfortable. If you kiss and the chemistry is good, chances are you'll keep kissing and if you keep kissing long enough you'll both end up so hot and bothered one of you will have to push things a little further. Don't feel obligated or pressured to go "all the way" (what does that even mean anyway?). Just do what feels comfortable to you both. Check in with each other and make sure everything's ok. If you're worried, it's a good idea to negotiate some boundaries. It's a good idea to talk about it anyway to get the question about STDs and such out of the way. But then you can talk about what activities you're both comfortable with. Speaking from experience, it really sucks to be in the moment and have someone tell you that you can't do something because that's their boundary. i'd much rather know before getting started that, for example, my partner isn't comfortable with me going down on her. Not that you can't make a split second, last minute decision that you aren't comfortable with something, but if you know something's off the table from the get-go it's nice to communicate that before hand, or if you know you only want to go so far in this particular instance, it'd be good to have that boundary set before you're both in the moment.