Just keep riding. It took me a long time to get to the point I can ride down anything and enjoy it. Probably 2 years getting 50-100 days the first two years. I started when I was 24 years old. I'm a slow learner and I was a terrible skateboarder back in the day, gave it up because concrete doesn't suit my bones or flesch. Don't expect to progress too quickly. If you have friends that are good riders and they are good friends go with them. Follow them but don't try to keep up all the time, stay within your comfort level. Most of my friends had been snowboarding for years before I ever went. They were pretty forgiving. I've never had a snowboard lesson and I think to this day I should still take one or more and ride it switch (because I SUCK at riding switch).
And to your rack issue, get a bag for your board and run the hitch mount
it'll keep the crap off your board if you go that route. Besides, if you can ride a bike down a steep incline and snowboard I think you should be able to lift your bike on to the top of your FJ
Just razzin ya. Enjoy