Lost Stars is incredible, amazing storyline, and gives a nice overview of that murky transition from republic to empire, and, most importantly, Empire to first order, with some large hints about Ep7.
It’s pretty much the best written Star Wars novel and beat standalone book going by reviews.
Overall it’s a great book and I think it’s classed as a young adult novel so it’s quite easy to read. It is technically a romance tho so I’m not sure if you’d be happy etc. I think there’s only one saucy scene in there, and it’s fairly ambiguous.