A program is a list of instructions. The computer follows them in order, from the top of the file to the bottom. That is the whole idea. Everything else is detail.
Most languages make you learn punctuation and structure before you can write a single instruction. Devlish does not. A Devlish program is written in near-English, so you can read one before you can write one, and you can write one on your first try.
Almost every useful program does three things: it takes some input, does some work, and produces some output. The program below asks for one piece of input and prints it back out. Run it, then change the value in the input box and run it again.
Press Run. The program asks for a name, then prints the value it received.
Takeaway
You just ran a program. Input came in, the program did something with it, and output came back. Every program you write from here is a longer version of that same loop.