https://experienceleague.adobe.com/docs/experience-manager-64/developing/devtools/developing-with-crxde-lite.html?lang=en#:~:text=CRXDE%20Lite%20is%20embedded%20into,properties%20and%20bundles%20while%20logging.
Please go through the link.
You should first understand the CRXDE console fully and how its working,
then you should learn HTL. After this, you can move to Java concepts
like Sling Models, Servlets, etc.
Seems like this is a service in which you are using tag manager. Service
is a Session based concept. You can create a different class and define
the tag logic there and call it in your service implementation and check
if its working.
If we have 3 components using same Clientlib and we are using all 3
components in page. Then how many times that clientlib will be called in
page and what is the reason behind it?