Welcome to the hobby.

Actually, the accepted rule-of-thumb is that if the publisher does not list a minimum or starting load, then back off the maximum load by 10% and use it as a starting load.

But, PLEASE, PLEASE, PLEASE go buy at least one published reloading manual. Read it throughly BEFORE you start to realod anything. Read it again. And then set down a written set of procedures based on what you have gleaned from the manual. Print these out EVERY TIME you go to the reloading bench and follow them, checking each step off as you complete it.

That may seem like a lot of "overhead", but I've been reloading for 38 years now and I have never had a squib load or uncharged case. That checklist will save you a lot of trouble and aggravation in the long run.

Good luck.