I finally finished my first project (took a while, to say the least) and now I have trouble rendering it in the right quality. I've tried it several times, but I always had bad quality and <30 fps, which I find unbearable.
Any help would be appreciated.
Change the comp frame rate to 60 in the comp settings.
My first question is are you sure you want 60 frames per second? The standard is 29.97, 23.976, 24, or in Europe (PAL regions) 25 frames per second. Not all media players will even play at 60 frames per second.
I would use the Adobe media encoder and a YouTube or Vimeo HD preset to render my deliverable. When you say that your project plays back at less than 30 fps it makes me believe you are rendering with the default settings in the render cue. This will give you an uncompressed file that will probably never playback at full speed. Your compositions should always be created with one of the standard square pixel presets in the composition settings unless you really understand why you would use a non standard comp size or frame rate. Unless you have a complete understanding of pixel aspect ratios and codec format restrictions and specifications you should not create any comp, even using a preset, that has non square pixels.
It would be a good idea to watch these three tutorials. The last one is on rendering.