Vienna is a cool opening, lots of fun for sure. Against d4 if you want something fun where your opponent won't know theory try the dutch... It can be hard to play because you're opening up the king by pushing the f pawn, but it's similar to the vienna in that respect, and you're already playing those kinds of positions with the vienna. But it's an attacking opening and you're guaranteed to have a fun game... Just focus on king safety would be my advice.
For a defense against e4 maybe take a look at the petrov, very solid and at your level you won't need to know as much theory as in the italian or ruy lopez or something like that, since your opponents won't know the petrov lines.
If you want some introduction to these openings just search for hanging pawns <opening name> on youtube
i am rated around 700 and i have had great success with the vienna as white and in general the GothamChess e4 repertoire on chessly. there are many lines in which black has to be very careful not to get a lost position. even if black survives the landmine of traps that is the opening, the attacking potential is tremendous.
however with black i really struggle. against d4 i currently think i can use the budapest gambit, but if anything else is better pls recommend that and against c4 i can play 1...e5, but for e4 i need a nice weapon that doesn't need that much theory but works almost as well as the vienna. i get that as black it's a bit harder to avoid playing defensively without resorting to unsound gambits (well at least that's what i found based on research) but there has to be a way to play a bit more aggressively.
just a few things:
-i don't really want to study any sicilians unless there is a way to do so without having to intensively study my theory.
-i like the king's indian defense but i feel that it's a bit too theoretical just like the sicilian.
-examples of aggression with games or smth attached (with comments explaining some ideas behind the opening) are appreciated
-it's ok if the opening isn't filled with deadly traps that make the opponent lose in 10 moves. i just want decently aggressive middle game play (although traps are fine as long as the opening is still decently sound).
thanks in advance for any replies.