Hello, Ohayo, welcome to the Forums!
1) The sentence such as it is makes me think of someone repeating instructions. A:"Now, remember, what do you do after you find the wallet? " - B: "After I find the wallet, etc etc". Yet, if you found a wallet, let's say yesterday afternoon, and if you are relating what you did with it, then the whole sentence should be in the simple past: "After I found the wallet, I immediately went to the police and turned it in".
2) As the moment of the action is clearly stated - yesterday night - the whole sentence should be in the simple past: "I called you last night, but you were not there. Where were you?"
This is only my opinion...