Shorts, Bibs tights, base layer & or short sleeve jersey, long sleeve jersey, windproof top, socks, shoes, overshoes, gloves, buff & or skullcap, helmet, eye protection would be the basics, also a gilet, and waterproof top could be added.

Would suggest staying with cycling specific clothing, it's specific for a reason, even things like gloves and socks, they have re-enforcement where it's needed for cycling, non-cycling specific ones will wearout quicker / be uncomfortable without this.

Find a good LBS, there are plenty around, and have a look at what they sell, fit is more important than brand, Endura, Altura and Lusso are good brands a lot of shops stock, Wiggle DHB range is well regarded. Planet X also does a range of good / cheap golves, you just say you are in the north; they are in Rotherham (Magna), that is either very north, or just quite south depending on your definition of the north.

Also, Aldi & Lidl have some very good cycling promotions throughout the year, so keep an eye out on them for this, but you always need to be quick, i.e. within the first 10 minutes of the stores opening when they have these promos.

Brands to probably miss due to cost are Assos and Rapha, both very nice, both very expensive,