You need to enable the system select knob to both on the trim panel. The startup tutorial doesn't mention this. I tried taking off and had the same issue. The taxi takeoff tutorial mentions it.
Anti-skid should be off for the ship. The purpose of the advisory, which is different than a caution, is to remind you the switch is off. That's important say, you depart the ship, hit targets over land, and for whatever reason can't make it back to the ship. Scanning the advisories should remind you to flip that switch prior to landing at your divert field. I've seen that scenario play out in real life, but the pilot forgot to engage anti-skid. Ended with a rescue det to the beach to fix the jet which had brake damage, and was off a runway.
sideshow's post in Took off, but it's all over the place was marked as the answer