1.I don’t like this scene or I didn’t like this scene
If I watched a movie last week/month/year and now I want to make a discussion about it.
2.if I have changed my mind, I have to say “At first I didn’t like it, but now I like it” or “At first I don’t like it.

Question

Answer

1 - I didn't like the scene when ...... they first found the tomb.

2 - At first I didn’t like it, but now I like it.

Answer

1. "I didn't like this scene" is correct because "I don't" means that you're talking in the present tense (for example while watching the movie)

2. "At first I didn't like it" is correct. For the same reasons. Btw "At first i don't like it" is always wrong because at first implies that you're talking about something in the past. 
Hope this helps. Good luck^^