Your picture, top right of any page → Account settings → Wallet, in the left-hand menu. Both balances are on the one screen.
They are shown together, which is exactly why they get confused. Read the next step before acting on either number.

The short version: Credits are money and behave like it. Points are a benefit of taking part, and they work in one place only.

Twenty-four months after they are issued. The clock runs from the moment they were earned, not from your last visit, and it runs separately for each batch.
Qualifying activity extends them — a new membership, or registering for another eligible conference. Staying involved is the only thing that keeps them; there is no way to buy more time.

Send four things: your name, the email on the account you are signed into, what you expected to see, and the membership, registration, refund or publication it should have come from.

No. Points are spent on publishing, at the Rights Agreement stage of the journal process. Credits are the balance that spends anywhere in CGScholar.
By registering for an eligible conference, or by becoming a member of a research network. They are not for sale.
Yes — twenty-four months after they are issued. Qualifying activity extends them: a new membership, or another eligible registration.
No expiry is stated for Credits. If a particular balance looks wrong, ask support about that balance.
Check which account you are signed into first. Most missing balances turn out to be on the account the membership or registration was actually bought under.
It is a stage of getting an article into a journal, and it is the moment Points can be applied to eligible publishing options.