Removing unused services along with related package

I am new to RHEL, I have a scenario in which I installed base OS via minimum installation and I installed my related custom rpm's for my application , Its size is around 2.5 GB. I need to reduce the size of this OS by removing unused services and rpm's.

At this stage I don't have idea on which is needed and which is not needed, Is there any way to uninstall all other packages except running services, I started my services and everything is up and running so with that setup, what could be the easiest way to reduce the size?

my Os details: Red Hat Enterprise Linux release 8.0 (Ootpa)

Regards,
Gobi S.