Hey there! Welcome to the site! I ran my first half-marathon in April and it was amazing! The whole entire experience was nothing I expected! I also don't have the CGM and I use the minimed paradigm pump. As I was training for my race I found I was taking great care of my diabetes. I was on a pretty strict schedule and diet so that helped! I went about my routine without changing any pump settings or insulin doses.
On race day, I kept my pump on and wore a SPI Running Belt that I purchased from Dick's Sporting Goods. It worked perfectly! I had my dad meet me at certain check points with my blood glucose monitor so I could check my BS and bolus accordingly. At these check points I also consumed GEL packs that I also purchased from Dicks Sporting Goods.
I think that if you stick to your regular "diabetic routine" throughout training come race day you will do great!!