Ok so the Evan's Gambit is a good opening to try, as you get a big centre for the sacrificed pawn. 4. d3 can always be played, but not necessary as there's no attack on the e4 pawn (that's sort of the point, like especially with Nf6 lines where you want to play a slow Italian game). Perhaps one fun one is as follows:
It was played in the match of 2020 between Dubov and Karjakin. It's an interesting opening and definitely a dynamic one which not many people are aware of.
Otherwise you could just try the centre game with 4. c3 and 5. d4, which sometimes sacrifices a pawn but you get some nice compensation with a strong centre and nice development.
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what's the best line for a casual player, not a beginner, aiming to improve after the line 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5? Is it better 4. c3 or 4.d3 or other? i mean a line with fair tactical chances but not crazy theory to learn or complex positional ideas that can also be an investiment for future growing of opening repertoire?
thanks.