arm knitting does use vast amounts of wool though,
Oula...and produces very niche articles. Otoh, there has never been a better time to take up general knitting. Starting with fairly simple things (hats, scarves, T-shirt style jumpers), it is very possible to make lovely artefacts just by learning half a dozen basic steps. Casting on, casting off (often called binding off), knit and purl stitches, increase and decrease. These will give you all the knowledge you need to make almost anything.
Wool. For the longest time, I avoided both very fine and very thick yarns - double knitting on 4mm needles accounted for almost everything |I made. However, this is the age of You Tube tutorials, internet podcasts and online shopping. I have learned more in the last few years than I had in the previous 50.
It is peaceful, even meditative. Slow and calming and highly useful. Maybe start with a simple cowl or scarf in garter stitch. I was given 'Vogue's Book of Knitting' as a gift - can be had for £20 and a useful addition and overview to the history and methods of knitting.
Drops and King Cole sell reasonable pure wool (merino). You might want to avoid drapey yarns such as alpaca or cotton just yet, and try a basic merino superwash. John Lewis also sell Novita yarns, West Yorkshire Spinners and the more spendy Rowan.
Podcasts and Tutorials - Purl Soho, VeryPink Knits come to mind. Best site for general info and forums - Ravelry - a free and accessible resource for patterns, forums, advice and a million other things. If you do one thing, join Rav.