It's rather easy when you get into it. I suggest watching some YouTube vids on it. Buy if you have questions, a lot of us here have them and will be able to help.
Just make sure you plug your ESC cable into the correct port and right way around.
Bind the Tx and Rx together, then calibrate the...
With those angles front and rear and the aluminum backstop, you won't need metal straps. Velcro will do fine, and won't cut into your battery.
I would also allow room for neoprene to be stuck down inside your homemade battery tray. I see you already thought of this 😜
Neoprene Rubber Sheet Solid...
Your car looks like it is designed to run counter-clockwise correct? If so, you have a big aluminum backstop. You just need to keep the battery from going front to back and lifting. I'd probably be fine just cutting slots through the chassis and using velcro. If something happens and your car...
There are lots of battery trays out there for various vehicles.
https://www.horizonhobby.com/product/battery-tray-2-dbxl-e-2.0/LOS251098.html?gad_source=1&gclid=CjwKCAiA8YyuBhBSEiwA5R3-E37hnsxXyDXdDnealDOqZS3kBu0karrFw77r7WOx2guD6YzkhuRN2BoCuLsQAvD_BwE