New to me truck has thrown 3 codes already. Needing help

[Thomas Sword]

I have a 2007 Chevy silverado 5.3. The 3 codes are P2635, fuel pump "A" low flow/performance.

P069E, fuel pump control module request MIL. money light. 

Those 2 are confirmed. The pending code is a P0455, evap. Emission system, leak detected, gross leak/no flow. 

I've checked the fuel fuel pressure and key on it's at 70psi. Running it's at 60psi. But when I turn the truck off i can watch the pressure rise to 85-90psi. 

Cold start it fires up no problem, only after a trip to the store.....5-10 miles and it has an extended crank time. Any help would be much appreciated, I've only had the truck for 3 days.