gear for beginner...stay in first, second, third, fourth, fifth or sixth, anything beyond that and you are becoming a intermediate to advanced rider.
If you are talking about gear to wear and or put on the bike well than that's a different matter. Start out cheap for clothing, you won't need anything more expensive until you start averaging more than 20 miles a day and 50 on the weekends. Jerseys and socks you can always buy cheap no matter how good you get because a $15 jersey or sock will feel just as good as a $100 jersey or a $30 sock, but as you ride further you will need to get nicer bike shorts or bibs but for now a $25 to $30 dollar short will work. Buy a cheap seat bag, make sure the bag isn't real small, a bag like the Topeak medium Aero Wedge pack bag is a great bag for just $20. Stock the bag with a new tube in it's box so it won't get punctured by other stuff in the bag, a good set of tire irons like the Soma steel core levers or Pedros plastic levers, get a patch kit that includes glue, patches, and piece of sandpaper, keep a couple of hand wipes that come in small individual wrap (I get mine for free at restaurants like rib or chicken places!) use those to wipe your hands off when you're done with a flat or repair. You need a pump, for the time being just get a cheap one like the Hurricane Air Scepter Mini Pump, it will only cost $14 on sale right now at Performance bike, it got high reviews so it's not a bad pump. Get a floor pump so you don't have to work like a maniac on steroids to get air into your tires every day using a mini! Don't go crazy on price right off the bat for a pump, the Nashbar Earl Grey floor pump got high reviews but only cost $30 which is great if you have kids bikes as well to pump, or if you just have your bike to pump you can go to Walmart and get their Airglide 500 or the Bell Sports Air Attack pumps for under $17.
If you don't know how to fix flats LEARN! There are numerous videos on You Tube that will show you how, then practice, practice, practice.
Once you've been riding for awhile, like a year or more than you can look into buying some better stuff after the cheap stuff breaks, but till that happens save yourself a ton of money and start out cheap just in case you decide you don't like biking, which I hope that doesn't happen but the odds are between 73 and 80% against you, so fight for it and defy the odds...not for us but for you!!