Oh...a couple other things...
Take a look at NC window tint laws and be sure you're within them. Apparently it's an inspection item.
https://www.ncdot.gov/dmv/title-registration/emissions-safety/Pages/window-tinting.aspx
Quality of tint:
If you don't want the window tint to change color on you within a few months, do NOT buy the dyed tint. It's the cheapest and, as "cheap" would imply, WILL have fade issues. Ever seen cars with that purple looking window tint? Yeah, it started out a shade of black.
Metallic or "metalized" film does not fade like the dyed film. On a physical safety aspect, it also increases shatter resistance of your window glass (meaning it'll help hold the glass in place instead of exploding all over the place if broken). It's great a blocking UV and heat, and reduces glare. However, it may reduce radio signals within the car somewhat...meaning you might have a little poorer cell phone reception.
Hybrid films have both dye and metallic components. They hold their color pretty good, but will eventually change...it takes longer.
Carbon window tint has a matte finish. Pretty good at blocking IR and does not fade.
Crystalline tinting, which is something I just learned about, is clear, but provides IR and UV blocking.
Ceramic window tinting, another newer type I didn't know about until now. This will not block signals, like metallic tinting can. Gives shatter protection, blocks UV up to 99% and IR up to 50%, and resistant to fade and glare.
If you want to practice, buy some of the cheapest tint you can find and have at it. The technique for installing it is identical, regardless, so why waste money on the expensive stuff to learn on.