ya these things are not jets !
They take awhile to build up some speed... a few minutes at level flight. Look for the speedometer... "air speed indicator" for those purist and wait till its over 200 before working any hard maneuvers. Each maneuver is going to bleed some of your speed away, the harder the maneuver, the more speed bled, so keep an eye on the indicator.
After take off, let the plane climb out for about 5 minutes, then level for a minute. After that do a slow gentle turn to one side or the otherpushing the nose down just a bit. As the field that you took off from comes back into view, level off and build some speed. Once the nose hides the field, push the stick forward to dive at the field. This will really build some speed, and you'll be able to do a number of manuvers with-out to much stalling. If your speed drops below the magic 200 again you will start all over. Learn to keep your plane fast and maneuverable.
Welcome to Aces High!