Sandysings19 I'm going to write down some basic explanations of Stellar terminology. Maybe it helps you in resolving the issues.
An account consists of 2 two parts:
- Private key - Starts with a S...
- Public key - Starts with a G...
Each private key has a corresponding public key. If you know the S... key you can always generate the G... key. If you enter on this website: https://www.stellar.org/account-viewer/#!/ the S... key it will show you the corresponding G... key.
But if you know the G... key you can't generate the S... one.
In Stellar an account hold your XLM balance. If you know the public key (G...) you can send funds TO this wallet. You can safely share this key with people that you would like to receive xlm from.
The private key (S...) allows you to send funds FROM your wallet. Everyone knowing about ti can send XLM out of your wallet. That's why it's really important to never shear this key with anyone.
Each account must hold at least 1 XLM. If you try to send less than 1 XLM to an empty account your software should warn you that you can't do this. In your case you were told that the account is not "activated". So each account that has more than 1 XLM is already activated and doesn't need to be "re-activated".
Wallets are apps (Stargazer, Solar, ...) that helps you to work with your accounts. Wallets usually let you manage multiple accounts. If you download a new wallet it will often create an empty account for you automatically, but to transfer any XLM to it you need to transfer more than 1 (for reasons mentioned earlier).
I think that in your case you have 3 wallets (a,b,c) and multiple accounts (*) with different amounts of XLM:
- Old phone:
- New phone:
b: Solar (? XLM)
c: Stargazer new
Notice that you also can have the same account in 2 wallets if you import your private key. In this case, If you send XLM out of any of the phones it will automatically be reflected in the balance on the other phone.
You don't need to use any wallet app. If you store your private key (S...) securely you can always access your funds through this website: https://www.stellar.org/account-viewer/#!/ and send them to anyone.
Try to write down all the private keys you have on a paper and check on the above website how much of your XLM each account contains.