Can't draw on new panels and timeline won't open

I started using the software last night, and it was working fine from what I could tell. I opened it again this morning and made a new panel, but I can’t draw on it. I tried the brush and pencil tools, but it’s not doing anything. When I try drawing on one of the panels I made yesterday, it erases what I had there. I think I accidentally turned on some sort of erase mode or something without noticing, but I don’t know. I added gifs of me trying to draw on both an old panel with something already on it and a new blank one.

Also, when I try to open the timeline window, nothing happens. All the other windows open when I click them on the windows tab, but the timeline just doesn’t show up.