Sweatier, tireder, more rushed, less well fed people than you have made clothing on sewing machines, you too can make clothing on sewing machines.
I recommend a Brother or a Janome, you can find those at stores like Walmart, and Singer has a really janky reputation for their machines of the last couple decades. If you have the time and are machine oriented and have the good luck to find a vintage Singer (or almost any vintage machine, really), by all means buy and restore that piece, it will treat you right, but Brother or Janome is the way to go. (Also, you don't necessarily NEED a sewing machine, but if you can pull together the funds for one it helps. If all you can manage is a sewing needle and a spool of thread and spending a lot of time hand-sewing for a couple hours a night for weeks on end? Yeah, you can make really good clothing that way too. It just takes longer.)
Other brands for inexpensive but decent quality supplies: John James (needles), Dritz (seam rippers, measuring tapes, chalk sticks), Coats & Clark (thread), Gutermann (slightly more expensive thread), Wrights.
Invest in an iron and figure out a place to throw down a towel and press everything. My sewing got 50% better just by pressing all the seams after I sewed them. It doesn't have to be a big investment, just get the mid-range iron at Walmart instead of the absolute cheapest. If you have shitty tap water, maybe get a jug of distilled water too and keep it by your iron so you don't use the tap water.
Rit is (or was for the longest time) a terrible dye because it tries to be all things to all fibers. Different types of fiber need different types of dye: plant based fibers (cotton, linen) act different with dye than animal based (wools) which act different than synthetic (polyester, nylon, etc). Rit does now sell at least one type of fiber-specific dye! If you can afford it and find it at Michael's or wal-mart, look for dye that says it's specifically for cellulose (plant) or protein (animal) or synthetic (polyester) fibers. If you can't afford fiber-specific dye or can't find it, don't sweat it, lower your expectations a bit and take your time and try and do test pieces if at all possible; you can work through an astonishing amount of problems by adding or subtracting heat, salt, time, labor (standing over it with a big dye-only spoon and stirring endlessly), etc. Craft forums can help guide you here. How do you find out what kind of fiber you're working with? You do a burn test, and craft forums, CraftTube, etc will help you here.
Search out videos on: felled seam, flat felled seam, and french seam. These are different ways of sewing enclosed seams so that your fabric doesn't fray nearly as badly. If you're not confident on these at first, you can also use FrayCheck. It's a glue for the ends of fabric and you can get it at WalMart.
This is all very overwhelming? Start small. Make a skirt. Make a cloak. Make a vest. Make something that's a few pieces of rectangle or a circle stitched together. Decorate it how you want! Write down all the skills you practiced. Did you learn how to do a French seam? Did you learn how to sew on a button? Did you learn how to read a sewing pattern, or what a grainline is, or how to thread your new sewing machine? Write it down! Make a list of all the things you know. Because over time you will realize that you know things, and you will go, hey. That skirt's just a few circles and some sewing and ironing and a lot of lace added onto the edge. I can do that.
And you can. I promise. You can do that.
