So currently I’m working on my code for a stoplight and I’m fairly new to this coding language. Could someone direct me to what prompt would allow two loops to run at the same time.

You cannot run 2 loops at the same time. You can make it appear that they run at the same time. If you give us an idea of what you really want to do we can probably help.

Loop() loops, use that.

Have a look at how the code is organized in Several Things at a Time

Note how each function runs very briefly and returns to loop() so the next one can be called. None of the functions tries to complete a task in one call. And there may be dozens of calls to a function before it is actually time for it to do anything.