I don't want to seem presumptuous or that I'm a know-it-all, but the majority of people I've talked to that were knowledgable about cigars, and the majority of people on cigar forums, say that 70% is too high for cigars, especially cubans. I keep all of my cigars at 70 degrees Fahrenheit, but at 65% relative humidity. Never have burn issues. I have had issues at cigar stores/lounges where the cigars have been overhumidified and led to plugged cigars, draw issues, burn issues, etc.
But first things first regarding your humidor:
First, do the dollar bill test to see how the seal is on the box. Here's a link
Then, if you have a good seal, then follow the instructions here
to properly season your humidor. It's pretty easy.
Next purchase some humidification beads. The two most popular are Shilala beads
and Heartfelt beads
Then purchase a digital hygrometer (this Xikar
is what I have), and do the salt test
on it... Or if you're lazy like me, buy a Bovada Calibration kit
and throw your hygrometer in there.
Once you have all that stuff, you're good to go. You'll only need to occasionally wet your beads with distilled water (or use the indirect approach they advocate over at Shilala) and you'll be at proper relative humidity. Then throw your cigars in there and call it a day. Depending on how old your Esplendidos are, they may need more time to mature, but that's a decision you'll have to make by smoking them.