I wouldn't really focus too much on the Vienna at 1500. I would just watch some YouTube videos about it. You can also play some games in the Vienna.
Vienna book?

The Vienna is a great opening. As for books, check out this past discussion:
https://www.chess.com/forum/view/chess-openings/vienna-game-20

many books and other resources on Vienna Game provided here...
Introduction To The Vienna Game & Gambit...
https://www.chess.com/blog/RussBell/introduction-to-the-vienna-game-gambit

I've been wanting to delve more into the theory of the Vienna game and stuff like that but the resources on the Vienna are so scarce from what I've found (my book only has like 4 lines for the Vienna gambit). Does anyone have any books in mind that can go more into the small details and more lines or do I have to get a course for that?
The Vienna Game and the Vienna Gambit are different things. The Vienna Game refers to lines where white doesn't play 3. f4.
Try to get hold of the 1980s Batsford book. It covers both. It won't have changed much because it's been out of fashion.

https://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwjDnav69P7wAhWZ2dUKHRdHCfUYABAHGgJ3cw&ae=2&ohost=www.google.com&cid=CAESP-D2mhEpUFVamPaPxURagTK4dABnGpSwWGfdc_0ONgSUQz8nsvwKrJjw-ikmFhqWCPJYP9G-yvLNEtpZvzM6ig&sig=AOD64_1sE9lmjF_-CpQRo0UfIh3qlffeHA&ctype=5&q=&ved=2ahUKEwidp5r69P7wAhWNkhQKHUTgCZwQ9aACegQIARBt&adurl=
Think it was this one I had.

I've been wanting to delve more into the theory of the Vienna game and stuff like that but the resources on the Vienna are so scarce from what I've found (my book only has like 4 lines for the Vienna gambit). Does anyone have any books in mind that can go more into the small details and more lines or do I have to get a course for that?
The Vienna Game and the Vienna Gambit are different things. The Vienna Game refers to lines where white doesn't play 3. f4.
Try to get hold of the 1980s Batsford book. It covers both. It won't have changed much because it's been out of fashion.
Yes yes, but the Vienna Gambit derives from the Vienna game so I put it all in one thing. Thank you for the link though

Well, my understanding is that the Vienna is 1. e4 e5 2. Nc3. Then it diverges. The Vienna becomes the Vienna Gambit if 3. f4. Anything else and it's the Vienna Game, unless it's tranposed out of the Vienna say by 3. Nf3. The three main moves are 3. f4, 3. Bc4 and 3. g3. The latter two are Vienna Game. The former is the Vienna Gambit.

The info I gave you was correct in 1987, when I learned it. But things change.
I played it when I took up chess. I didn't care for the Gambit, where black equalises easily. Therefore I played 3. Bc4 for about a year and a half to two years. It's less tactical than some other double KP openings and I used to try for a positional edge. I could draw with much stronger players using it. If white can play f2-f4-f5 then white is often winning. BUT black has the Dracula Frankenstein, ...3. N x e4 and then d5, winning back the piece. That's very hairy. If I was the stronger player I would go down theory and try to win. Playing against stronger players, white can bale out, into a dead drawn position. But white sometimes wants to win so I gave up playing 3. Bc4 and started with 3. g3. That was ok but not great, playing a KIA. So at that stage I took up 1. c4 and my win ratio trebled at least.

Long live the Vienna !
https://www.youtube.com/watch?v=rRwd94jQmCE
I've been wanting to delve more into the theory of the Vienna game and stuff like that but the resources on the Vienna are so scarce from what I've found (my book only has like 4 lines for the Vienna gambit). Does anyone have any books in mind that can go more into the small details and more lines or do I have to get a course for that?