How do I find a list of all movies or tv shows which premiered before their theatrical release?

No one is going to have an accurate list of ALL such.

At best, someone might have an attempt to list all they can find information on, but there are an insane number of movies and TV shows over all time, and they don’t all have data on all their premiere screenings. And the data there is, is likely not all in one place.

There are probably some sources that make valiant efforts, though probably mostly for the USA, or for Germany (I bet the Swiss might be most likely to have a complete database on Swiss films and TV shows).

I am a little confused by this question, by premiere you mean those private ones they do for critics? I thought every movie with a theatrical release did that because you usually see critics reviews in movie trailers?