EMB-170 First Officer reported that they failed to raise the landing gear immediately after takeoff; citing distractions from FMS issues and wake turbulence as contributing.

Narrative

Flight from DFW to ZZZ. I was the pilot flying and the Captain was the pilot monitoring. During rotation on takeoff the airplane went into roll and flight path angle which I called out to the Captain. I flew the plane while the Captain trouble shooted on the guidance panel; restoring proper lateral navigation and vertical navigation modes. During this time we also twice encountered wake turbulence from the departing airbus in front of us adding to the distractions. Flaps were then raised on schedule and it was at this time that I called out that we were not getting the climb performance that we should be. The Captain began trouble shoot the problem while I continued to hand fly. I called for auto pilot on at 5000ft in order to help the Captain troubleshoot the problem. He asked ATC to level off which we did so at 6000ft. It was at this time I realized and called out that the landing gear was still down. The gear was then raised and we continued climbing and on course uneventfully.Suggestions: Turn autopilot on sooner so that workload is lowered and both crew member can better attend to the issue.