Hey mate, could probably start a thread in the general techniques area if your unsure as it might generate more traffic however in response to your query.
RDWAHAHB (Relax, Don't Worry and Have A Home Brew)
But in all seriousness 1.011 FG is normal. It's on the lower end and may give a more crisp, thinner finish (nice for clean crisp beers) as opposed to an oatmeal stout or similar which may finish higher around 1.020.
Generally in general the FG is a combination of things, however yeast attenuation does play a major part. So say you start with an OG of 1.040 and end up at 1.010 your yeast have consumed 3/4 or 75% of the sugars.
Thats why the strain of yeast you choose is important as some attenuate or work more efficiently than others.
A note on the fermentation temp, 22-24 is probably a touch high for generic yeast but may be ok. Try and keep it around the 19c mark if you can.
Sugar unless it's inverted can, and I say -can- (because you added a tiny amount and I don't want you worrying) impart cidery flavours. Best practice is to buy dextrose from a brewing shop if you want to thin the beer out (sugar will add alcohol but give no body, it can thin the beer out meaning the FG is lower and the beers mouth feel will be lighter) or more dry malt extract if you want to keep a more medium body.
So, in summary. 1.011 is completely normal. Ferment a touch lower if you can. Try and use quality yeast that you buy ontop of the kit. Sugar will 'thin' a beer and can provide cidery flavours.