Camber profile snowboards have better edge hold and more pop. This shape is great for jumps and charging. It's the more aggressive profile option, but it doesn't let you get away with bad riding habits.
Hybrid profiles are typically softer, washy and more playful. This shape is great for buttering and jibbing. It is the less aggressive profile option, but it can let you get away with bad riding habits that feel proper, like riding down hill doing counter rotated turns.
Flat or Rocker profiles are typically really soft and are more playful. These shapes are great for buttering and jibbing. They are the less aggressive profile options, but it can let you get away with bad riding habits that feel proper, like riding down hill doing counter rotated turns.
Most board manufacturers offer a size chart on their product website. Have a look at the size chart to see which board length is best for you.
If your boot size is 10.5 or larger, you will need to ride a wide board, otherwise you will have too much toe or heel drag affecting your riding. If you have a boot size less than 10.5 you can still ride a wide board, just know you will need to work a little harder to get from edge to edge.
For more information on buying boards, check out our blog on the subject: https://snowboardaddiction.com/blogs/latest-news/10792969-what-to-look-for-when-buying-a-snowboard