1) My timeline seems to be gone. When I click window -> timeline, the timeline shows, but it seems to be emty, and i cant drag any videos into it. How to i get it back?
The Timeline Panel is a panel--not something that holds your edits. You need to open your sequence in the Timeline panel. In the Project Panel, find the sequence you've been working in, and double-click it; it will load into the Timeline Panel where you can continue working on it.
2) I want to set in subtitles. I go to Title -> New title -> default still. In the title display, i set up a text and set the timeframe to 25 fps. Problem is that i dont know if thats the correct way to insert subtitles, if thats the right way to set the timing and lenght of the subtitle. Also, when i did it in this way, the subtitles did not apear on the exported file. What did i do wrong?
Premiere Pro doesn't create subtitles You can create titles (that's what you did), but that simply creates a title clip in your bin (or in the Project Panel). You need to edit those into your sequence like any other piece of footage, and you can set any duration you like for them, since they are synthetically-generated footage.
> Im new to premiere
I strongly recommend that you spend some time working your way through the basic learning materials before you jump in to work on a project. Doing so will prevent a lot of frustration.