You can not determine your public key by receiving or sending from an address. The trick is when you reveal your public key then any watch wallet can see all your transactions under that key.

If you feel like your public key is exposed then you get another private key /public key set up and you send your sats to this. You can still keep the other original wallet for purposeful interface. Just use it as a hot wallet for smaller transactions. Or just use it to sign stuff.

Either way you can keep and control how the information is used.

I used Atomic wallet when I was shitcoining. I had the key phrase and I had no idea that my re-used address was a liability. What was worse is that the basic Atomic wallet Bitcoin address was the public key! It was stupid. I wrapped up my Bitcoin and I saved my key and emptied it. I still watch that wallet and have the private key.

Since that time I've migrated several instances and I'm much better at only using the public key to watch and not disclose or show. I have generated addresses that I use for individual transactions and those addresses do not reveal the public key or private key.

If you read Mastering Bitcoin by Andreas Antonopolous. You can see how key generation has many derivative uses and you can use subsets of keys to make keys that are like subnets of the Internet. This allows you to assign blocks of addresses that fall under a derivative without exposing to top echelon.

The easy way is to just get a new seed by careful generation and send UTXOS to a new addresses generated due each transaction and keep the pub key under your hat.