Hi and welcome to the forum:
As regards coming to grips with your new camera, to add to the excellent offerings from my colleagues, you may want to check out some of the following tutorials:
(1) mavin eos r100 tutorial - YouTube
As a wildlife photographer myself, I suggest that for a safari trip, you contact the organizers and ask them what kit you should be using. Not long ago, I coached a couple who went on safari and from the photos they returned with, they were taking many of their shots in the 600mm range and above. Frankly, I suspect that with the gear you have it might be better to rent a separate kit and look at something like an EOS R6II and the RF 200-800, or the Sigma 60-600s. Your RF-S 55-210 is likely to be way short for many opportunities.
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
