Hello! I wonder if there is a way to buy pets from others? For example, buy pets with good battle stats. It is possible? If so, where?

i'm pretty sure it's against the rules to sell a pet! as per the rules in the adoption center

rule 33:

people adopt out pets for free in the adoption center subforum. keep an eye out there, and you'll occasionally see some with good stats. some people ask for applications / ideas of what you'll do with the pet, but they cannot and will not ask for anything in exchange for the pet.

Thank you all!

As an additional note, pets with stats over 2000 will lose 10% of their stats when transferred

Just as a heads up if you did find a statted pet for adoption. It also doesn't take super long to get stats that are good enough to battle with - with the recent BC reset, I started training a third battle pet just to use up the eggs I'm getting as loot. She's tier 2 currently and able to get through the first 5 levels of battle quests for 1500 EXP per day (I haven't tried non-quest battling with her yet though to see how many wins in a row she can get on a challenger). I've heard if you're able to autotrain in the early tiers, they go super fast as well, but I can't speak from experience on that. I always did manual training

And how to battle efficiently? Does it require special weapons?

At lower tiers, not really. This is what I have right now for my tier 2:

But I already had the quill and rainbow vortex and use them with my tier 8 and 12 pets too, and I also already had the minotaur knocker. I wouldn't say any of those are necessities in the early tiers.

I personally don't know a whole lot about the strategy side of things so I would recommend asking on the Battle forums or poking around this thread for some useful info: Useful Battle Links

How to get the minotaur knocker?

Okay, ill see!

It's a prize from completing the 2012 Bobblehead collection which are only available by buying them from other users or when they occasionally get rereleased somehow through like the Crystal Shop or somewhere

There's also an ENTIRE forum dedicated to battling and trading pets. It honestly truly doesn't take long to get a pet to T4. I find that forum quite helpful in strategic training and good weapons guide per tier.