Ok, just for the record; you have a TRX450ER.
The air intake is under the seat and is located on the rear of the top of the airbox cover. You could just take the top off the air box if you want to.
Since you haven't ridden it in 5 or 6 months, I'm going to guess the carb needs to be cleaned - valves should be fine - new spark plug would still be a good idea.
Drain the gas and put in some fresh 92/93 octane. Any starting fluid will work. Go to Walmart and see if they have any. If not, any auto supply should have. Using starting fluid you might have to throttle up while cranking.
PS - I have a sister in Marietta, she used to live in Lawrenceville and I worked for a company that had a division in Peachtree City. I always wanted to try riding up Stone Mountain