Your fitness level is good. But start getting some road running in - you'll need the stamina - preferably with standard issue boots. DPM trousers and backpack with increasing weight, because that's what you'll be wearing on most of the tabs - plus weapon.
One of the biggest problems on basics is foot blisters mainly down to feet being soft and getting used to boots. Get yourself a few pairs of 1000 mile socks - my son swears by them and rarely gets a blister, even on deployment.