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The Springboks back row forward will join Ulster on a two-year deal from the Bulls in the summer after the conclusion of the Super Rugby campaign.
"I can learn a lot from Rory Best. I'm really looking forward to playing with him," said the 25-year-old.
Botha currently has a shoulder injury but he expects to play again in March.
"I had surgery last year but it's looking very good at the moment. I'm on track and I want to be back in action in March."
The twice capped Botha says conversations with fellow South Africans Marcell Coetzee and Franco van der Merwe convinced him to move to the Irish province, despite the team's struggles this season.
"The people I've spoken to say there is a good vibe there and that it's a good culture. Obviously, they say the weather is not the best but it is something to adapt to.
"I've heard about the performances this season but they have had a lot of injuries and you are not always able to do your best when there are a lot of injuries.
"They are not where they want to be at the moment but I know Ulster is a team that is striving for greatness," added Botha, who has made 46 appearances for the Bulls.
Van der Merwe is departing from Kingspan Stadium at the end of this season to join Cardiff Blues but Botha says his compatriot had nothing but good things to say about the Belfast-based club.
Injury has prevented flanker Coetzee from beginning his Ulster career following his move last summer but he is expected to make his debut for the Irish province against Edinburgh on 10 February.
"I spoke to Franco van der Merwe and for me to have Marcell there is really good for me because we are good friends.
"(Like myself) Marcell is newly married also and I think that is a good thing that my wife can be with his wife.
"My wife is very excited about the move because the farthest she has been out of South Africa is Zanzibar and it is a very exciting thing for us to go north to somewhere we have never been before.
"She is studying to become a chartered accountant. She just did her honours now and that will be a very good thing if she can go over with that (qualification)".
Botha made his Springboks debut against Italy in 2013 but suffered a knee injury just four minutes into his second test against Scotland.
He returned to full fitness and captained the Blues to the final of last year's Currie Cup and Ulster's director of rugby Les Kiss believes the player will be a major addition to his pack.
"He is very aggressive in attack and his ability to get over the gain line will be especially good for us," said the Ulster boss.
"Arno is also strong in defence, he's a nuisance at the breakdown and he's a good lineout option, so he has a very well-rounded game."
South African forward Arno Botha says he is "excited" at the prospect of joining Ulster and learning from one of the game's "great leaders" Rory Best.