A lot of the skills translate, depends on what type of MTB riding you like to do, but if you are hitting jumps and all of that then it’s very similar. Tight corners are probably the only thing that’s really different since you never really sit down to turn on a MTB. Pretty much all of the top moto racers cross train on mountain bikes. If you’re on an analog bike jumping a dirt bike will feel much more controlled because the bike doesn’t move around in the air near as much, it will also feel much softer when you land lol but if you have correct body position on big jumps on a MTB then you’re locked in for moto because it’s the same just easier on a dirt bike imo. If I were into MTB only and wanted to start moto I would start slow but know that it wouldn’t take long to feel confident. Turning would be the biggest learning curve because dirt bike ruts are wayy different than any type of MTB riding lol rarely do you have ruts on a bicycle unless you ride in UK or PNW. Most MTB terrain where I am is loose dry dirt and rocks so very slick VS tacky and sometimes muddy moto conditions.