How and where I can find 'year end HSA value'?

You get Form 5498-SA from your H.S.A. bank (administrator). Form 5498-SA reports contributions to your Health Savings Account (HSA), Archer MSA, or Medicare Advantage MSA, Fair market value of HSA, Archer MSA, or MA MSA .

I'd suggest checking your account statement for your Health Savings Account or contacting the provider/administrator of your HSA.

which entry on the Form 5498-SA is the Year end HSA value?

The value of your HSA on December 31, 2019 (for tax year 2019) is in box 5, "Fair market value of HSA, Archer MSA, or MA MSA".