I am planning to buy a mining rig here in bitcoin, but this is my first time.
What would you suggest to me?
what should be done first? Also, what type of mining rigs should I buy, there is no problem with the capital,
I just really want to try, and at least before the Bitcoin halving comes, I have already started this kind of thing.
Your help is much appreciated

I was once where you are today, trying to find the best asic miner that I can get for Bitcoin mining, but it's not about the capital only, I know you are in haste but do not underestimate the importance of electricity consumption, this was where I messed up some time ago and I ended up selling an Asic miner back, you need to first figure out how you are going to pay for the electricity bill if your grid bill is cheap then you can buy and run any Asic miners you want, you only have to go with Asic miners that are profitable, if your electricity is not cheap, find something else to do with your money, or you will end up regretting your decision.
Do some calculations on your electricity bill first, how much you are paying per KW then you can continue your mission of acquiring an Asic miner or more.
A new ASIC for 100-110 terahash and a good noise box can be bought within 2200-2500 dollars. Some of the profit can be spent on electricity to buy more ASICs, and not save money to pay electricity bills. But if electricity is expensive, then it is better to buy coins.