1. Chartplotter/fishfinder.... the combined units are great and you really don't need the all singing all dancing one. The Garmin Echo is a great unit, couple fo hundred quid and wil give you all you need. The Navonics web app is good for planning and their mobile app will provide a good service (according to people with it) but not tried it myself.
2. Vhf radio...fixed or portable or both? I have both, start with fixed (more range) and add a hand held later, can pick both up pretty good 2nd hand.
3. Flare kit....good question, I carry a couple fo smokes and that's it, coded boats 'need' a certain amount and type but for the modern world I think other options (strobes, plb, gmdss) are a better option.
4. PLB...McCurdo has a great reputation and what i carry, annoyingly the batteries are nearly as much as a new one, so beware of 2nd hand battery dates.
5. Automatic life vest...just bought the family new Northern Diver ones, others will swear by their preferred make, mine is a Kru and fits me lovely, and that's the key bit. Fit. Must be comfy or you'll hate it and not wear it.......
6 What Anchor type - depends, I carry a (hated on here) grapnel anchor, a sea anchor (drogue) and when going out where I may need to anchor a CQR. Where are you going, what's the sea bed? I don't anchor often, maybe when throwing out a fishing line so the smaller one works for me.
7. Wheels- Bigger is better to a point, alloy wheels may look good, but really don't like salt water, stick with steel and paint them
A good tyre is important as there is limited, if any, suspension on a boat trailer and the tyre takes all the abuse.
8. Level 2 will be a great point to start, loads of training options out there. I can recommend some good ones in Plymouth if you wanted a weekend away. Look at your local adult education, they often do them. Or see who the local sailing centre uses up at HPP
9. Anything else you think i should need? Lots - but lets cover that later