Two Quick Questions

Hi everyone.
I have recently gotten into flight simulator and have got the hang of quite a lot of things now, however two things are confusing me. The first is flight levels. Earlier today I was told by ATC to "Expedite your climb to FL190". I think that this means something like (190 x 100) feet but I am not sure. Can someone please clear this up for me.
The other is the auto pilot. Now I know how to use the auto pilot (I can set it to a certain heading, course, altitude e.t.c) but for something reason whenever I disengage the AP the aircraft will suddenly veer in a certain direction, usually up. Anyone know why and how I can stop this?
Thanks
I have recently gotten into flight simulator and have got the hang of quite a lot of things now, however two things are confusing me. The first is flight levels. Earlier today I was told by ATC to "Expedite your climb to FL190". I think that this means something like (190 x 100) feet but I am not sure. Can someone please clear this up for me.
The other is the auto pilot. Now I know how to use the auto pilot (I can set it to a certain heading, course, altitude e.t.c) but for something reason whenever I disengage the AP the aircraft will suddenly veer in a certain direction, usually up. Anyone know why and how I can stop this?
Thanks