As someone who's had many lovers, I will say to you what I would have liked to know at your age;

Just be yourself, you don't have to try to be the best girlfriend he ever had, that state of mind is setting up for inevitable failure, if he's with you is because he likes you, if you feel a pressure to not be yourself 100% then it's not the right one for you even if you feel like he's the one.

It's not a failure to be alone also, don't be afraid to let it go if it's the right move, being single is okay and better than a unfulfilling relationship.

Also never put your friends aside your relationship, your friends are as important as your relationship, because they will be the first ones to see if the relationship is good for you or not.

And never try to avoid hard conversations, relationships strengh is in how well you can have those.

That's it, I am sure you two being great friends for two years is a good start to a healthy relationship!