RE: First Airplane engine
For your FIRST engine, I suggest a 2 stroke engine. They are easier for a newbie to set up and run, plus they are much cheaper than a 4 stroke.
Some good, reliable and USER FRIENDLY (see "runs right out of the box with little or no fiddeling with it" ) are Thunder Tiger Pro, Evolution and OS. With the OS stay away from the LA series. The difference in price between the LA and AX/FX series is minimal, but the performance/horsepower difference is VERY noticeable. I would also avoid the MDS brand - do a search on MDS and form your own decision on whether or not their nicknames (Mostly Don't Start, Metal Door Stop, etc) are justified.
Another possibility you may want to consider is the Tower/GMS engines. They have superb power, but do have one problem that I know of personally - they do not like to shut off with the transmitter.
Hope this helps.