You need proper snowboard boots...you will f'up your ankles riding in tennis shoes. Most people agree this is the most important part of your gear...but if you havent ever snowboarded, i would rent and be sure you like it before shelling out the dough.
Technine bindings size LARGE are for 10+ feet....you may need smaller bindings.
Most boards have a "front" and "back" an easy way to tell is if the board has any writing/text on the top, you will be able to read it right side up if you are standing at the back.
Any ski/snowboard shop should be able to do an edge sharpen for you, no specs required.