Check primersion.com/rc
You can see calculation of HP to RC, but its your to decide how much is enough. Usually I start with equivalent of 9HP which ahould be enough for a beginner and then I add 11HP equivalent if I see more is needed.
There is also a nice list of your delegations you can sort in many ways.
I didn't figure out yet how to review my delegations and cancel those which are not being used.
Thank you for the very quick reply, I will keep it in mind.
I know what you mean by the equivalent of 9, but that doesn't answer my question.
But thank you for pointing me to @primersion. I appreciate it.