I don't know how to reproduce my projects

I bought a focus card and everything is going well in terms of drivers and computer detection.

Cubase 8 detects and records it with microphone, with midi and with instrument by jack.

I am new to cubase and surely it is a beginner’s question, I am not able to play listen to my projects, I do not know if it is because of selecting the preset, or because of misconfiguration of an output channel.

I’ve tried exporting them from .cpr to ogg but they still don’t sound. Maybe it’s a problem with the recording volume.?

I would appreciate some help.

Really hard to give any advice because your description is very vague.
Seems to me like you just need to learn the basics of Cubase. Have you looked at the Cubase YouTube channel? There are lots of tutorials there, including some dedicated on how to get started, like this playlist:

Have you checked your audio connnections and configured the inputs and outputs for your new interface? When you record something, do you get an audio event where you can see a waveform?

I have already done all the steps you tell me, this all correct is saved in wave form but it is not heard, I guess the volume will be very low by default or something like that, I can not find the problem.