PD: I'm new to this and this is my first web application
It is very important, as a general rule, that you don't only learn express. Just because you can use express and nothing else doesn't mean that you should. Challenge yourself to learn the inner workings of how the framework does things, and how web apps, as well as regular apps, work.
Having this knowledge will make everything easier in the long run, but that isn't to say that you should reinvent the wheel.
Overall, use Express, but make sure you know how you could do it on your own.