Iron Man 2 takes place around 6 months after the first and finds Tony Start dealing with his declining health as well as the United States government wanting his suits technology. He is also dealing with the world knowing he is in fact Iron Man, including a rouge Russian scientist, because you know its always a Russian in these movies. This Russian scientist wants revenge against the Stark family for numerous reasons some of which are probably valid.
The movie itself is about what you expect, its funny, witty and full of excitement which is exactly what Iron Man is known for, tho once again the villain for me is pretty meh.Whiplash is just isn’t great. I haven’t read the comics, but I am told this is a common theme there as well. Visually the movie is great and the soundtrack may be the best we have seen in a marvel movie at the time it was released.
I doubt the movie is considered the best in the MCU by anyone, but I would be equally amazed if it was considered the worst by anyone. By all means watch this one, it is very enjoyable. Best wishes and may the gaming gods bring you glory.