Probably d4. If we look at the top level, then Magnus used to play e4 but he got closer to the top he switched to d4. Also e4 I guess has some drawing lines for black related to ruy lopez berlin wall variation. And e4 also allows sicilian defense which is considered a powerful defense. Maybe d4 is tougher for your opponent so if pick one, then d4.
interesting, thx
kings knight opening
queens pawn opening
and queens gambit
are all my favorite openings. im really new and 400 elo so if anyone has tips please tell me.