Vegeta is scared of beerus because he is a destroyer. And also because beerus used King Vegeta's head as a stool. All jokes aside,Beerus is extremely strong and anyone would be afraid of him. Why did Vegeta fall to the floor when meeting Beerus?
2) Vegeta's fear of Beerus
The reasoning for this is a time during childhood, when he saw his father utterly powerless and completely under Beerus' control. Considering how important Saiyan pride is to Vegeta, this scene understandably stuck with him, serving as the base for his own initial fear of Lord Beerus.
Vegeta is afraid of worms!
Shenron is often nervous around Beerus, trying to be overly respectful. When the eternal dragon is summoned by Goku on the Princess Bulma, he instantly becomes nervous when he sees Beerus there. For the rest of the conversation, Shenron addresses Beerus with honorifics and acts very humble toward him.
It's not that Beerus is afraid of beating up Vegeta, he doesn't want Vegeta and the gang to hate him. He's kind of grown attached to their antics.
Given that the two are on completely opposite spectrums of their tolerance for Saiyans, it makes sense for Frieza to be considered as Vegeta's greatest enemy, since he serves as the predominant threat to Vegeta's budding Saiyan family.
This is a transformation used by the Gods of Destruction and only those who have been trained in the ways of Destroyers. It takes time, but Vegeta always surpasses those who were once stronger than him, and with Ultra Ego, he will eventually surpass Beerus.
Monaka was initially described as being a hero of his home world planet, Wagashi. At some point in his past, he was said to have fought against the God of Destruction Beerus. He managed to cause Beerus trouble, which makes him later claim Monaka as the strongest fighter he's ever faced.
To pay them their respects, Beerus begins calling his fighters by their name instead of various nicknames he has for them. The prime examples of this are Krillin, Gohan, Master Roshi, and Piccolo, all of whom are acknowledged by Beerus upon their defeat.
Weaknesses: Vegeta is arrogant and prideful, and if overpowered by someone he considers below him, he can lose his temper. He also seeks strong opponents, and will therefore allow his opponents to reach their full power for the sake of a good fight.
One of Goku's biggest fears is losing his loved ones. Throughout the series, Goku has faced numerous enemies and endured countless battles, but he cares deeply for his family and friends. He has witnessed the deaths of friends and allies like Krillin, Master Roshi, and even his own father, Bardock.
Ota: Actually, Vegeta is rather strong mentally.
Even after seeing how strong Goku has become he never wavers in his quest to become stronger.
Beerus was afraid Beerus would cause Xeno to destroy his universe, not of Jiren himself. He was scared Goku would lose.
Beerus later attacked the king because he ordered for King Vegeta to give him the most comfortable pillow in the universe but was given the second most comfortable pillow and kept the most comfortable for himself (in the anime) or caused a big commotion (in the manga).
Majin Buu and Lord Beerus are the Only Two Fighters Frieza Fears, but Maybe Not Anymore.
Additionally, Beerus is not hesitant to kill other lifeforms, even his rival, Goku, as he threatened to destroy Goku if he got involved with Zeno and irritated or angered the Omni-King.
After Goku defeats Frieza, Beerus sets up a tournament between his Universe 7 and his twin brother Champa's Universe 6. After Universe 7 wins, Beerus wishes for the population of Universe 6's Earth to be restored.
Vegeta has seemingly been queued up to be Lord Beerus' replacement as the new God of Destruction, but Beerus' real successor is actually Lord Frieza.
As the series progresses, Krillin becomes Goku's closest ally and best friend as he fights every villain along with Goku or before him and is often depicted as the comic relief.
Krillin > Of all the human fighters, Krillin is probably the only one Vegeta has a decent respect for.
Back when BoG was released, it was stated that Beerus had to use 70% of his power to defeat Goku as a Super Saiyan God. Toriyama even stated that he considers Goku as a SSJG to be 60% as strong as Beerus, and in RF, Whis even suggested that Goku and Vegeta could defeat Beerus if they teamed up.
Whis is one of the strongest beings in existence, and interestingly enough, only his father and the Omni King are confirmed to be stronger than him.
Although Broly is thought to be stronger than Beerus, it can't be denied that Beerus has extra powers up his sleeve, such as Hakai. Beerus' status as a God of Destruction ultimately gives him the edge over pretty much anyone — including Broly.