Google Search Console Errors

Hi there,

I'm having some technical SEO issues, which seem to have only started in the past 9 months (after 12 years of plain sailing), and I'm struggling to fully understand them and especially resolve. I don't even know how many are important!

It's a SquareSpace 7.0 site, and I am normally slightly technically minded - though not an I.T. expert - but these have me flummoxed; and there's so many I don't know where to start.

https://www.sohovocaltuition.com/

1. Core web vitals: Why do the stats on about my desktop Core Vitals completely drop off occasionally? Currently my website has 0% good, 0% bad, and 0% ok urls. Even my maths knows that's not correct.
2. LCP issue: longer than 2.5s (mobile): I can't work out how to reduce this. Does it actually matter if my site regular ranks top 1-3 for my keywords? Is Google planning on changing the algorithm and should I get ahead of the curve?
3. Page with redirect: I only setup some of these (see attached). Where did the others come from? Some of them are real working pages, some are old pages, some are oddities created by SS (#1! and ?_escaped_fragment_=)  
4. Not found 404: Ditto - some are working pages, some are old pages, some are SS oddities...
5. Alternative page with proper canonical tag: Some are real, some are index pages, most are #1!
6. Two sitemaps: SquareSpace has two sitemaps - one HTTP and one HTTPS. Is this normal and ok? 

Any help, on any of them, would be greatly appreciated. Thanks so much.

Kind regards,

Jareth