Pull the nose up gently to take off as the speed gauge passes 75. More importantly, you'll get more points for every kill and every target bombing if you safely land. The airfield must belong to your nation. Touch down at the end of the runway, going 100 kts or less. You'll want to hit targets on the ground as well.
Fighters can use their guns to strafe a target on the ground.
Fighters and bombers can load up with bombs as well. In real life, planes took at least 30 minutes to rearm and refuel. Instead, land, quit and start a new flight. On the ground, you can chat with other players at your location by using the chat controls at the bottom of the screen. However, you can change your radio to any channel, from 001 to 999.