I think you should play the Italian game with white. It is such a beginner friendly opening. And with black I would recommend you to play the Caro Kann defense. It's so solid and you'll get very fun positions to play.
What's the best opening for a 700 elo?

There is no best openings. Stay with your Vienna. It is fine and you will learn a lot. As black answer 1.e4 (wich should be what you will meet in most games) with 1...e5. Then 2.Nf3 (if they play 2.Nc3 you already at home. If they play 2.d4 or 2.Bc4 to often you have to prepare on that, but until then just rely on your instinct) 2...Nc6 and use your opening study time on finding your answer to 3.Bc4, 3.Bb5 and 3.d4.

1. There is no such thing as a "best opening".
2. Your opening choice should be based on the type of middle games you're comfortable playing.
3. At your level openings do not decide your games.

I think you should play the Italian game with white. It is such a beginner friendly opening. And with black I would recommend you to play the Caro Kann defense. It's so solid and you'll get very fun positions to play.
Such bad advice. Do not listen to noob advice.

Play whatever you enjoy.
At the 700 level (and the 2300 level too) your best asset for improving your chess is your enjoyment of the game. That's what keeps you coming back, and it's what keeps you studying. If your enjoyment of chess started to wane, your interest in the game and your impulse to improve would fade away as well.
Play whatever is fun.

A new person at chess must learn how to lose. That is that. And that means you lose a game as graciously as possible. If it bums you out and you get upset you give yourself space to cool off and then move on. Everybody wants to learn how to win win win. But if you cannot lose properly you will always be an unhappy chess player.

A new person at chess must learn how to lose.
I must have lost THOUSANDS of games, with nearly a hundred of them being CFC-rated, over-the-board tournament games.
The single most important quality of a chess-player isn't visualization or calculation.
It's sheer, bloody-minded stubborness. It's the ability to fall flat on your face, lose in humiliating fashion... and then pull yourself back to your feet, give your head a shake, and play your next game at full strength. As if nothing had happened.

You will need 2 Black openings.
1 against 1.e4
I recommend the French
1 against 1.d4
I recommend the KID

The best one is the one you understand the most. So, play what you have traditionally played, but fully develop your pieces before attacking. Try to learn enough of the ideas to recognise when you are being threatened and how to develop. You are probably going to end up in 1.e4 e5 games and 1.d4 d5 games until you do better or get tird of them. Start with one for each of those then go from there. You can learn a new one when you get better.
I am currently studying openings but I can't decide which opening is the best. I ain't a scholar mater, I just want an opening that is easy to learn that doesn't risk anything. Currently I prefer Vienna when I'm white and I can't really decide which is the best to play when I'm black since I have to follow what white plays.