Hi,

thanks for your replies, here is my answer to your questions:
1. I'm not sure what year I started but maybe 2014: is there a way I can find out from the address what era does it belong to?
2. I was, am, and will always use Bitcoin Core full node only: i found a way to limit how many GB it keeps of the blockchain so I don't have the problem of disk storage anymore.

I got the confusion when someone said that if you keep using the same address over and over again then your wallet can get hacked. This story came at the same tiem as quatum computing fuss was going on. I always used the same address because it used to get confused between wallet and addrees: i thought they were the same. Now I still don't understand the following:
1. one wallet can have many addresses: i've tested this it's easy to confirm
2. The number of Bitcoins is contained in the Wallet, not in a particular address: not sure?
3. I don't need to create a new wallet.dat, i only need to create a new address in the same wallet.dat: not sure?