Here's my take on your question:

First off, most important thing you need right now is a release. I highly recommend the Tru-Fire Edge Buckle Foldback release for beginners and expereinced archers both. Shooting without a release is not only frustrating for new archers, but can also be dangerous, since poor technique can torque the string and cause it to derail from the cams, causing potentially serious injury to the shooter.

Secondly, take a look at the strings. Replacing strings and cables will run you around $100. If the strings are shot on your $100 bow, you may need to replace them immediately for safety, so you might have been better off buying a $200 bow with decent strings from the jump. Strings should be replaced every season or two at least, if not more frequently, for hunters, way more frequently for target shooters.

So then onto the specs....

Draw Length: Draw length is the most important spec on a bow, in my opinion. This generally needs to be set by your bow shop, and for some models, might even require new parts (like replacing Modules in Mathews bows). Since you're 6'2", assuming your arms about as wide as you are tall, then you likely need a 29.5" draw length bow. Most bows are adjustable between 25" or 26" up to 30" or even 32", in half inch increments. Go to a shop, try shooting a 29.5" bow, then have them check your form and see if you're overstretching or not extending enough. Have them adjust it to 29", or 30" and try it again.

Draw Weight: This is the second most important spec (really DL and DW are the only two important to me). Most guys are comfortable with a 60lb draw, with minimal practice. I only shoot 70-80lb bows, but I'm a glutton for punishment. Most modern bows will adjust DOWN about 10lbs from their specified maximum, so a "70lb bow" could be set anywhere from 60-70lbs, a "50lb bow" could go 40-50lbs. I personally would recommend you get a 70lb bow, then turn it down to 60lbs, learn how to shoot it well, then if you want more power/speed later, you can turn it up. If you buy a 60lb bow, you'll likely want more later, but can't get it. My 5'3" 125lb wife shoots a 54lb and a 63lb bow.

Axle to Axle length: Personal preference. Shorter bows are easier handling in thick timber or in a tree stand, but they also sacrifice stability. Longer bows are generally more forgiving for new shooters. Bows in the 32-34" range should be comfortable, assuming you have a 7" brace height.

Speed: Bow speed doesn't really mean much. I'm a speed demon, want as much momentum (rather than KE) that I can get, but it's not what kills. IBO speed, i.e. the number published on the bow, doesn't really mean much to most guys, since they're not shooting the same arrow weight or draw length as the IBO test standards. Since I'm a short draw shooter at 28.5", I NEVER get to shoot as fast as my bow's claim they can.

Let off %: Most bows are going to be either 65% or 80%. As a beginner, you won't be drawing 80lbs, so 65% will still be more than enough let off for you to hold. 60lbs at 65% let off is pretty easy to hold back.

One you missed...

Brace height: Brace height, in laymen's terms, and not so specific, is basically the length from the grip to the string, when at rest (not drawn). "Standard" is 7" brace height, but certain bows will be longer or shorter. Shorter brace heights are generally faster, but they're less forgiving for the shooters. Longer brace heights give up some speed, but they're more forgiving to new shooters, since there's less contact time between the string and arrow.

So, my personal recommendation would be a 70lb max bow, 29.5" with a 7" brace height.

Hopefully that helps a bit, rather than just adding to your confusion. Keep asking questions.