The Challenger has very good takeoff performance, so everything happens quickly. For the first few flights a heavier weight can help keep things in check. One of the key differences between A320/737 aircraft and the Challenger is there is no speed reference system on the Challenger. Instead the flight directors will give a fixed pitch target when pressing the TOGA buttons. Following the guidance from our subject matter experts, and adapting it for use in the simulation, we've got two easy ways to manage the initial climb, which can be remember as Pitch/Sync and FLC. Try both and see what works for you.
Pitch / Sync: Takeoff and follow the initial flight director pitch target. Accelerate in the initial climb maintaining that pitch, retract the flaps at VFTO+5 then at a safe altitude hold the “Sync” button and lower the nose to about 10 degrees to start accelerating. If using autothrust it can be set to maintain a suitable speed, but your primary control is pitch, which can be adjusted easily by holding sync and flying the aircraft to the new pitch attitude.
FLC: Takeoff and aim for the initial pitch target before selecting FLC mode to capture a speed of roughly V2 +20. At most weights this will result in a very steep climbout. At a safe altitude, increase the speed to lower the nose then retract the flaps at VFTO+5
A hybrid approach may be useful - remember unlike an airliner the Challenger has seats facing sideways - so while a space rocket climb profile can be fun, it’s unlikely to get repeat business for your VIP transport business.