>>1096805Fellow DIY seamster here.
>where to buy materialsFor modern tech fabrics, Ripstop by the Roll or Makeyourgear. For basic materials and leather,
>>1096962has the right idea with thrift store scavenging. You can occasionally find what you want at places like Tandy Leather, Hobby Lobby, and Jo-Ann's Fabrics, but they tend to be a little pricey and their selection sucks unless you order online (they rarely have free shipping).
>book/video guidesSinger, Husqvarna, and Swingline all have rather in-depth instructional videos on the setup and basic use of their machines on their website, otherwise there are some good YT vids. I can't find it now but there was a really GOAT one on bar-tacking.
>making patternsCut apart old clothes that fit you. Spend the $1.50 on an actual seam ripper. Use a glue stick or tack spray to stick it to cardstock or foamboard and cut out with an exacto knife.
>picking stitchesuh. Can't help you here, I'm using an old Singer Electric (yes, the 80+ year old first-electric-sewing-machine one). It does 1 stitch, the standard running stitch. It was my great-grandmother's.