Hi. I'm very new to AN and I need some help.
I want to make a short that's maybe 1 minute long. But, my timeline only goes to 26 seconds. How do I fix this?
There's nothing to fix, you just haven't added any keyframes out there yet. Sounds like you really need to watch a few tutorial videos on how the Flash/Animate timeline works.
Select last frame and click F5 in keyboard