To say usual everyday is more than a bit redundant, isn’t it?
All the verbs are in past tense except says. Fix that by changing it to said.
If you say the stranger looks like a younger version of himself, you’re saying the stranger looks like a younger version of the stranger, which is nonsense. Change himself to him. Then get rid of the comma after him.
He was out on his daily walk when someone who looked like a younger version of him materialized in front of him and said, “Dad, thank god I found you.”
(No, it is not incorrect to leave god uncapitalized. Is this character religious and actually thanking his deity, or is he just using a common expression from his culture even though he’s not a believer? I’m fairly sure the writer isn’t a theist, or they’d have made certain to capitalize god — theists are rather touchy about that, which is why telegraphs had to be typed in all caps.)