New to ebikes

I just purchase an xtreme xb-600 from an older gentleman for 400 dollars. Its less than a year old and has been driven only 4 times, and never depleted the battery. I have never owned anything like this, hell, i've never even road something more than a pedal bicycle. I don't know anything about these bikes, or the potential. But so far my purchase has been awesome, I have road this thing probably 30 miles in 3 days. I actually made myself sick riding it last night in 35 degree weather. What I'm here for is to learn more about these bikes, the community around them, and maybe modify. I had wondered if it was possible also, to add a small gas powered engine, and maybe run it on the pedal chain for more speed and distance. It is 8 miles to the next town, where all the stores, bars, areas of interest are. I live out in the country and work from home, so this bike has already seen alot of farmland, and is only for fun. So if anyone has any suggestions, tips, tricks, or general owners information, that would be great! The manual that came with it is kinda crappy, it seems general, and not specific to the bike at all, I didnt even know i could lock the handlebars til I was reading on this forum.