If you think you have something that will sell, try having a local screen print shop do your shirts until you make enough to buy better equipment.
i got some waterproof transperencies from silkscreenprinting.com but for some reason this has been my only problemThe Yudu may be a toy but it is not totally useless. You are far better off buying 3rd party supplies for it though (especially emulsion), look on Google or Amazon for suppliers. I kind of wish I'd bought one when it was $70 last year, it appears to have been discontinued now.
Don't expect to get it right on the first few tries. If your transparencies aren't dark enough, you can print two and stack them but you must make sure you get them exactly lined up (make registration marks) or have someone else print them - even pro screen printers often outsource their film positives. Go through and read some of the screen printing basics threads on this forum and look for videos on YouTube.
Even if the Yudu doesn't work out for you and you decide to build a simple screen press, a lot of people keep it to use as a light box. I think once you get the hang of it you'll like it, it'll still be useful for small proofing and things like mousepads.
im using some cheap printers i because at first i didnt know it was really important im using printers i used for school papersWhat printer are you using? The best seems to be an Epson with dye ink, but a lot of people say pigment ink (the 1100 or a dye printer that's been converted to pigment inks) works fine as well. If you have an HP they have funny ink chemistry that's designed only to work with their photo papers (which is why you can't use most of their photo papers in other brands).