Enter debug mode and press the bug at the top right and then check the views and the models and you will see what is printed in the dashboards, also familiarize yourself with said structure. Also download some OCA module that you think has interesting functionalities and take a look on how it works and how it inherits.

There is plenty of tutorials on the web as well. For example Odoo Mates (https://www.youtube.com/@OdooMates) has an extensive set of tutorials for several versions, but they are a bit slow.

Hope that helps. Take care.