Transmission will not engage?

It sounds like you are low on fluid. We should check the level first, this guide will help walk you through the steps:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

If the fluid level is okay, we should run the codes to see if anything comes up

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/automatic-transmission-problems

I have seen the pressure control solenoid go out and cause this issue here is the location of the solenoid so you can check it out. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.