First off, welcome to the hobby. Second, as others have said the color will be different with extract. The main reason for my post is something that I have not seen touched on yet. The SG is "Starting Gravity" which basically means the amount of sugar available for the yeast to eat. When you said "My current SG be down to 1020 and is it correctable?" When the yeast eat the sugar there is less sugar in the beer. Since the yeast eat the sugar and convert that into CO2 and alcohol. So your SG (should be current gravity reading) is 1.020. You need to check your hydrometer readings over a three day period, when there has not been any hydrometer change then you can bottle/transfer to secondary, whichever you plan on doing. I would not transfer to secondary unless you are dry hopping. So continue to check your hydrometer readings. When it gets to its lowest number, that will be your FINAL gravity. You can use the FINAL gravity in a formula to determine an approximate alcohol percentage. Hope this helps. Enjoy the hobby, it becomes addictive. Also read all you can on this forum and buy some books. Cheers