First of all, as a man, you should be responsible for your actions. Although both of you are willing, men should take on more responsibilities, comfort their girlfriends and don't show depression and cowardice. This will scare your girlfriend. If you have the determination to go all the way with him, you must be kind to her, because girls should be with you wholeheartedly, so don't hurt her.
Then confirm whether the safety measures are done well. If the safety measures are done well, there will be nothing and everything can go as usual. If you get pregnant unexpectedly, the suggestion is to tell your parents frankly and not let the school know, otherwise the whole school will know about you two, which is not only a punishment, but also a girl's reputation is likely to be unbearable to do stupid things, so parents can handle it privately, just to establish a relationship. If you really don't want your parents to know, raise money for an abortion yourself, but you must go to a regular hospital. After all, if it is not handled properly, it will still cause a lot of harm to girls. At this stage, you should also comfort your girlfriend's mood. After all, girls nowadays are very fragile.
If you don't plan to be together forever, don't break up with your girlfriend right away. After all, breaking up just happened not only hurt my girlfriend, but also left a bad reputation for myself. Break up again in the future, but it is not recommended to break up. It is best to be together for a lifetime.
I strongly don't recommend having sex in high school because it's too fragile. Both of them gave their precious things to the uncertain future. Many couples in my high school have had sex, but few of them can be together after graduation. Many of them have been confirmed by their parents and have broken up. So it's best to go on together, or don't go this step in person.