So to be even more helpful to the Op and try to explain where some of the advice is coming from here.

OA torch sets are often available used on Craig's list. The Op lives in or near a major city, I'd be surprised if there wasn't a used set listed every month or two. They tend to hold their value well, once the initial depreciation has happened. So if the budding builder decides to give the building thing up they can recoup most of this investment. Having a bit extra ability, heating wise, will be learned to be nice sometimes. Being able to have a number of frames (and practice) before one needs to replace/refill the tanks is also nice. Having the ability to have different tips and therefore flame size is nice.

Miters can and are done by simple files, tube blocks (self made often) and a bench vise. You'll need all these to do the after finishing work any way. Angle control can be dealt with by a scale drawing and cutting out a template to hold against the tubes/joints. One of the most regarded builders uses only files to miter with. I've tried many other methods (Joint Jigger, lathe and milling machines) and currently use a bench grinder to rough cut and a file to finish my miters. Takes about 15 to 30 minutes each because I'm slow and like beer. Only when I'd be getting paid for my building would a faster mitering method make investment sense.

Alignment can be done by a drafting comparison, careful point to point measuring for the geometry aspects and builder's wheels and good eyes for the flat to plane aspects. I've posted a number of times about using non precision tools to get forks and frames straight. Some builders use counter tops, milling machine beds and doors for their flat surfaces (if that is what you feel the need to use). I only got a used steel flat surface plate after making a dozen+ frames first and learned that I wanted to do this for the rest of my life and wanted a faster path to alignment. Note I don't say a better riding alignment.

Building one joint at a time, tacking as you go with alignment checking is a valid process and doesn't need any formal jigs. Some sort of tube/angle holding method will be needed but this is part of the discovery/experiment process all budding builders go through. Hose clamps, Vee blocks. Wood struts all are simple low cost "jigs' to deal with tube to tube holding. Again my first, about, dozen frames were built w/o any formal jigs.

Taking a course will quicken up the learning curve A LOT and minimize the pot holes along the way. There is something to be said for learning good technique (like how to hold and move the torch/flame or how to draw a file across a fillet) that will make these steps go easier. But many hundreds of nice frames have been made without any formal or paid for instruction. I've taken two paid for classes, the first after about 8 frames and the second almost 30 years later. Both were worth it for my world.

There can be a lot said for getting proficient at what ever you are doing. But when one's building for their selves how efficient they are is pretty moot. How fancy is their workshop is only a personal choice. Only when going pro do these really shift. Then one's efficiency, repeatability, quality control, integrity, insurance, range of fitting and design experience, ability to manage the business and money side, the reputation and perceived value to your customer make the difference to both you and your customer. This is when having done the practice and testing (destruction, cutting up to check penetration, alignment documentation) start to be needed, expected and dangerous if not present. The claim of needing to build 200 frames first is more of saying that it takes a lot of practice before many of these aspects of being a skilled and profitable builder who makes well fitting and durable frames is accomplished. We all (customers and one's peers) hope/expect that a pro is all this.

So back to the Op. Don't give up. Listen to all and try to pick what advice you can work with. Don't be afraid to fail and understand that learning can be frustrating and gratifying. Please feel free to ask for more help/advice. Some of us will work with budding builders off line, I'm open to this.

To 6D- Sorry that your early experiences with the on line advice forums was so frustrating and off putting. But you did manage to keep going and now you are giving advice. That's the way things can work. Put in your time and offer back where you can. Andy.