There's lots of ways to go on a welder.
The cheaper you go, the sooner you'll want to replace the machine. If you've decided to become a career welder then... ehn, even then, you're 14, buy the cheapest POS you can.
My usual mantra is to buy the cheapest tool that still looks like it'll work 3 times. There is a quality of tool that will literally break before you've used it 3 times, those are just a waste of money that are more or less scams. I shattered a ratcheting screwdriver the other day, by hand, tightening up some screws on a coffee table. Shattered the cheap mechanism. Should never have bought anything that terrible (bought it for a friend, and I figured most of the time she'd be asking for help anyways and I'd probably bring my own tools). But a step up from that is just a cheap tool, which is what almost everyone will want and use. The cheap tool will teach you what you don't like about that cheap tool, it will let you find out what kinds of things you care about and don't care about, so that if you do want to get a nicer tool in the future, you'll know which one to get with which features. And cheap tools are usually 10% the cost of good tools, so, even if you completely waste your money on the cheap one, it's only a 10% mistake. Compare that versus the "buy once cry once" always buying the nice tool, you'll never know whether you would've been fine with the cheap one. You lose almost every time.
Another way of putting it... would you rather own 10x as many crappy tools that work okay, or 1/10th as many tools that will last you a lifetime? It's only 10% extra to have both if you're wrong every time, and 90% savings if you end up not needing both. So, you come out ahead if even 1/10 tools was okay to buy cheap.
It's really hard to beat a cheap fluxcore welder. It's an awful machine for welding sheet metal, it's hard, it wants to burn through or not at all, but it's doable. It takes some extra prep and a dolly (copper slab you hold against the opposite side to soak up extra heat) if you want it to look nice, but it can be done. I merged two whole GTs together with my flux core. I've used MIG, I've used Stick, I've used TIG, i've used laser welders, spot welders, etc. I'm cheap so I use the flux core welder.
You'll hear advice like "Oh that's just a cheap POS you'll be selling for $40 after a few months". Well, if that's true, then look for the person who bought it and is selling it for $40 after a months and buy it from them. They're not really out there.
I say buy the cheapest flux core welder you can find, and then buy the cheapest auto-darkening welding helmet you can find (probably $40), an old leather jacket from a thrift store ($10), and some gloves.
Option B, if you have time at home for projects but you don't have extra money... I can tell you how to build a flux core welder from 2 broken microwaves, a junk nicad drill (with dead batteries), the brake lines from a bicycle, and a few bits of scrap material you probably have lying around. For nearly free, using almost no tools. Probably will take you a Saturday or a weekend.