I am hoping this is a stupid question, but I am stuck and at wit's
end. I am at the part where I emerged from the mine/caves, and saw the
bridge with the combines marching across, and defeated the two antlion
bosses. Now I see a cage with an elevator in it and a generator

Just started driving in Under the Radar and I've found a garage with what
appears to be a lift, a locked cage with a rocket launcher, and an upper
platform that's inaccessible. Any clues on this puzzle? (Preferably just a
hint.)

I have Half Life 2 and Episode One and have heard about Episode Two but I
can't find anywhere to purchase it on Steam.  All I see is this Orange Box.
Can I buy Episode Two on it's own like I did with Episode One?