In reply to Herdwickmatt:
Extrimtextil is excellent for technical fabrics, and they have just restarted shipping to the UK albeit with a minimum spend.
For a fleece hoody/jumper I did a lot of research into patterns and found this one to be well reviewed:
https://www.extremtextil.de/en/fleece-pullover-and-vest-pattern-gp512.html
it’s very similar to a Patagonia Synchilla style. I adapted the pattern slightly by making the body 5cm longer and arms 10cm longer but only found this out by making a test version with some cheapo fleece from the local fabric shop.
The UK based fabric shops Pennine Outdoor and Profabric are also very good and ship quickly but tend not to have the branded cordura etc fabrics.
For getting the basic bag making skills, I would highly recommend some of this guys tutorials. Helped me get up to speed with webbing, zips, templates etc
https://m.youtube.com/c/MackWorkshop
good luck, enjoy, and my top tip would be to not use your expensive fabrics on the first attempt!