When many people want to learn to weld, they don't want to spend any real money......in case they turn out to be totally incapable and have to eat the cost.
Anybody can Mig weld.....you CAN do it. Don't get caught up in whether all your welds are going to be works of art. Most amatuer welder make some pretty welds and some that aren't as nice.......but they all seem to hold things together.
The number one BIGGEST MISTAKE you can make is buying a cheap flux core welding machine. Buy a decent machine and you will find welding to be much easier to do.
There will probably be someone who tells you how happy they are with their flux core welder. If flux core welders were good you would see everyone buying them. Nobody ever buys a flux core because it works better than a gas suppied mig. There are a lot of cheap welders sitting on shelves in the corner of someones shop and they don't even try to use them anymore. They convinced themselves that they themselves are the problem not the welder.
Start out with a decent welder and you will be successful. Then you will get even better over time. My son was 1800 miles away and I told him over the phone how to do it. 10 years later he still has the same machine and welds just fine.
My suggestion is to buy one of the "Auto Set" type machines with 220 volts. I can see you cringe at the thought of spending that much money.....but you will love it. Most new welders have no idea how to set the correct wire speed and ampherage for their project. The machines have a reference guide, but they don't look at it. With auto set all you have to do is set one dial to the wire size and the other dial to the thickness of the material and start welding. You can adjust it if you want to. Don't get just a 110 volt machine. If you want to be able to weld things thicker than sheet metal you want 220 or you will always be fighting to get decent welds. If for some reason you turn out to be that one person who is so inept that you can't weld, you can get almost all of your purchase costs back by reselling it. Nobody wants to buy HF used welders.
There are lots of things to consider when buying a welder that you won't think about on your first purchase, and it takes too long to point them out and tell you why. I would suggest a Miller 212 as its a full size machine and is built on a cart. That means the money you spend for a cart to hold a small machine isn't needed. Buy a bottle, don't rent. Miller isn't cheap, so you might look at a Hobart. You lose a few features but still get a decent machine. Things like the size and length of the weld cables and infinite control rather than stepped control go away as price decreases. If you are serious about learning to weld don't make the big mistake of "cheaping out". You want a machine that will last you a lifetime and you will be glad you bought 220 & a good machine. If you go the other way you are in for a lot of frustration and failure.
Check out IndianaOxygenCompany on Ebay. Thats where I bought several welders from and they usually have good prices. I have no affiliation other than being a happy customer.