when buying a deck there are multiple shapes and sizes to choose from. if you are just starting then i would suggest starting on a 7.75. most people sell decks with griptape but i would recommend you finding that out first. when buying trucks all you need to do is make sure they fit your deck e.g. 7.75 deck would need 7.75 trucks. wheels come in loads of sizes small for street skating and big for ramp. if you are just starting i would go for 54mm - 56mm. bearings are what make your skateboard move and are measured by ABEC, this is NOT how fast it goes but it is how long it will last. but most ABEC 1 - 3 are slow. bolts should come with a board but i have found to be let down before so always ask.
if you are buying a full set up out of bits from my shop and want my to set it all up for you just send me a message and ill do that for free.