.45 is a good one to start, low pressure, plenty of latitude for different components, powder charges etc. Easy to look into the case to make sure you have proper powder fill, easy to pull w/ plastic hammer when you make a mistake. 9mm is good too, but its easier to work w/ fatter components
Back in the day, I started w/ 38 Special...not a great choice for a new reloader. Way to easy to double charge a case.
I agree .45 is one of the easier calibers to reload - although I have had my fair share of issues as everyone does when they are getting into it.
Take the advice of those who have been through it - Go to a reloading class, pay attention, ask plenty of questions.