I normally recommend you get a tent advertised for one more person than you plan to have sleeping in it; for one person, get a two-man tent. It gives you room to wiggle, some extra room for "dump the load inside the tent when it's raining and then spread it out while keeping everything dry," and some room for gear. Do you really want to leave your camera in the bar bag, and risk it being stolen, when you might have room to keep it beside you?
Others may have different opinions, of course.
Two other recommendations: (1) Decide what you want, but try to stay flexible. Are you willing to spend $200, $300, $800? Can you carry an extra pound to save some of that? Two pounds? Do you want the lightest possible weight (probably a bivy sack), or are you hard over on stand-alone?
Once you've got initial answers to those questions, (2) go to an REI or similar store. Try to do it during a weekday, or early on a rainy weekend. Go through their selection, and try putting up the tents that match your criteria. You'll find some take an architecture degree to set up (how will you get that done in a rainy dusk?) and may be very light, and some are no-brainers but weigh more. If you're over 5'8" or so, crawl inside the erected tent. Ask yourself some questions: how do you fit (the REI tents usually have an "extra" version that'll fit taller people), how much room you have to sit up, and stretch out your arms (like you would putting warm clothes on in a cold morning). How easy is it to get out of the tent and fly in the dark when your bladder is really, really full; or to get back in without soaking everything in the tent when it's raining and blowing?
Pick out the tent you like best and buy it.
Once you've bought your tent, don't look at any tent sites or discussions -- especially this one! -- until you've toured with it for a week or two. By then you'll think more about the owl hooting over your head at 2:00 in the morning than about how you might have saved 2.75 ounces for only $55 more. There's always another choice you could have made. After you've built up a few memories with new gear, you won't care anymore. You'll end up happy and content, which was really your goal to begin with!