I got boxes and boxes of the old fabric as part of an estate, well my sister in law's mother did and I was offered the fabric. lol
Start with simple styles, patterns marked as easy. Stay away from anything too fitted to begin with. Don't be afraid to experiment with bargain priced fabric before working with the more expensive fabric. Keep notes as you experiment so when you work with that pattern again you know any adjustments that you made. Especially if it is something that ends up fitting perfect. Start with easy to work with fabrics as well. Cottons, fleece, etc.
I have a couple of shirt patterns that I use over and over again making my western shirts. They fit well and are easily adaptable to changing the style slightly. Both of the shirts shown are from the same pattern but using very different fabrics. The blue is a cotton with metallic collar and cuffs (metallic fabric very difficult to work with). The red and black is red satin collar and cuffs and a sheer fabric that actually changes from red to purple to black depending on the light. Both of these are also very difficult fabrics to work with. Somewhere I have a picture of a third shirt made from this same pattern that again looks very different.
Have fun with it.