It is the site blockchain.info that asks me to finalize a transaction because my funds are on an imported address is I would like to put them on my wallet
You imported the address only into Blockchain.info. Transactions cannot be done without a valid signature using the private key that corresponds to the address you are sending the funds from. Where did you get the address from? Do you still have the private key? A private key should start with either 5, K or L.
I buy bitcoin via bitboat, the worry is that I give to receive my bitcoins an old bitcoins address that I had noted on a note I did not know that changing it all the time.
I have never had a private key
Hmm you never had a private key to begin with? Then those bitcoins on that particular address were never yours to begin with!
You should know that the address you
own should have its private keys embedded on the app or whatever wallet you are using and you will be able to extract it any time you like. Well in this case it seems that you don't even know what a private key is, then you don't really own whatever bitcoin is in there in the first place.