Don't bother if you didn't like 7 and 8
The movie is garbage, I'm not going to spoil it, but you can almost the plot anyways. As the title says, if you didn't like 7 and 8, you aren't going to like this one. I would be really bummed out if I had paid to see the movie, but I was actually invited by my stepdad.
This new trilogy seems completely pointless. It's just a money-grab. Of course that was always going to be the case, but at least make an original story instead of rehashing 4-6 with a worse story.
But basically:
First order loses, Palpatine returns and gets killed by an unworthy protagonist.