MIchael, welcome back to the hobby. Yes, there have been a lot of changes, but much of the old stuff is still around. In military models, 1/35 and 1/72 are the most common, with a lot of good recent releases. With space models, I"m not as familiar, but Dragon are releasing some new items from the Apollo missions, I believe in 1/72.
With the military kits, is there a specific time period or subject that you prefer, like Shermans, softskins or modern? If there is a particular kit or item you want to know about, just ask here in the forums, or check the reviews. There will be lots of info provided. As for paint, I was using Pollyscale, which has been discontinued, so I am looking for a new paint line as well.
Great nations do not fall because of external aggression; they first erode and decay inwardly, so that, like rotten fruit, they fall of themselves. The strength of a country is the sum total of the moral strength of the individuals in that country.
Ezr