Can I recover my Bitcoins bought in 2009? I am a complete novice to the whole Bitcoin thing.  Can someone advise me please? I bought Bitcoin in 2009 when it was first launched. I  had downloaded the wallet(been told it was a Bitcoin qt wallet)to my desktop back then but no longer have the computer now. I do not remember the 12 word phrase, but I do remember the email address and the password. The email service provider shutdown in 2017, so I can’t access the original email. I only did one transaction and that was to buy Bitcoin. My questions are...
Would the transactions be recorded in present day Blockchain? Or are there many different Bitcoin Blockchains at present or just one Bitcoin Blockchain?
Can I recover the Wallet ID just by knowing the email address and password?
Are my Bitcoins lost forever?
I am getting lots of people telling me different things, so confused at the moment. Any help would be greatly appreciated. Many thanks
I had downloaded the wallet(been told it was a Bitcoin qt wallet)to my desktop back then but no longer have the computer now.

If you do not have the computer, you will need the wallet file or a backup of it.
As Pieter mentioned in a comment above, the software would have originally just been called 'Bitcoin' at that time.

I do not remember the 12 word phrase,

Mnemonic seed phrase backups for bitcoin keys did not exist in 2009

but I do remember the email address and the password.

The bitcoin software does not have anywhere that you would register an email address. Perhaps you were using a bitcoin wallet service of some sort? (though none existed in 2009, the earliest examples would likely be in 2010-11)

Would the transactions be recorded in present day Blockchain?

Yes, all transactions are stored in the chain for all time. If you owned coins and did not spend them, then they will still reside at the address you last sent them to. The only way to move them from there is to sign a valid transaction with the private key for that address.

Or are there many different Bitcoin Blockchains at present or just one Bitcoin Blockchain?

There is only one Bitcoin (BTC).

Can I recover the Wallet ID just by knowing the email address and password?

If it was a self-hosted wallet, then no. If you used a wallet service that is still around, then you will need to contact them to hopefully recover your account.

Are my Bitcoins lost forever?

If you cannot recover the wallet (private keys), then yes. They will unfortunately remain forever locked.
Your best bet is to very carefully check over any hard drives / old storage mediums you may have, as well as email addresses, or any other places online you may have stored your data. You could also look for physical backups of your keys (&quot;paper wallets&quot;), which would likely just be a printed sheet of paper with private and public keys listed for said address.
Best of luck!