Everything Dies When I Go to Start SOLVED!

Thank you everyone for you responses. Everything is BRAND NEW. I believe as some have mentioned there might be an issue with the terminals at the battery.
Battery terminals can REALLY screw with you. They can get a thin oxide that LOOKS OK but won't carry current. Get yourself a battery cleaner tool / brush and clean the posts and clamps up shiny then install them

HOW TO TROUBLESHOOT

You say it won't crank. This actually makes things easier because it's a problem in the "primary" part of the power---the starter/ battery cables--and possible starter relay.

1...to eliminate the starter relay, jumper across the two large bare terminals......the big stud and the "square" screw terminal.

2...This only leaves a few possibilities............no particular order.......
A......the battery clamps/ posts
B......the battery cables, corroded internally or poor crimps
C......the other end, eyelets, loose at connection, rusted, poor crimps
D ......the wire from the solenoid "square screw" down to the solenoid or it's connections
E.......Unlikely trouble in starter as you say you are losing ALL power. ARE YOU? To be certain, turn on the headlights and try to jump starter at starter relay. Do the headlights go out?
F....Dead or defective battery

HOW TO FIND. Learn to use a meter or even test lamp

1...Put meter lamp onto engine block and stab into top of NEG terminal. Jump relay. If you get a reading or light, the ground cable is bad or bad connections in that path. Put meter / light onto battery post clamp and stab into NEG cable. If you get reading or light, with starter jumped, cable clamp is not making connection to post

2...Same thing on positive cable

3...This gets "3 handed" It is best to go direct to battery POSTS but you just can't "2 handed"....clip meter or light to one batt clamp, stab the other into top of the opposite battery POST. Now jump relay. LOSS of light or reading shows battery is down, dead, or just plain defective. A BRAND NEW battery can be defective

Twice in my life I've had batteries that evidently broke the internal connections, and did similar. It would just plain lose all power, just like a switch.