Hey I'm the new guy
You could expect to see a good gain of 10-15 lbs in this easy cycle. Get your diet and training in order first. That determines your outcome and results. Like previously posted, you should run it every 3 days or less because of the prop in it, but I've seen success at a Mon and Thurs schedule. Make sure and get some L-dex if you are concerned with bloat. Since this is your first cycle, 500mg is not too low or too high to begin with. If you're going to shut down your system you are only getting about an extra what...80-90mg of additional test above your own natural level if you go 250.
Just my .02
peace