As anybody can become a Bitcoin miner by running a software with a special hardware.
Yes, anyone can try and set up their own mining rig but that doesn't mean they will be successful in mining even a single block. There's a competition among miners and whoever has the higher hash rates has a higher chance of finding the next block.
but how the Miners gets their money, who paid them?
Each miner are rewarded with 6.25 BTC for every successful block they mine + the transaction fees each Bitcoin users pay.
Note that the block reward will decrease every halving which is after 210,000 blocks are mined (approx. four years).
To illustrate, it was 12.5 BTC/block from 2016-2020. Since the 2020 halving, it was reduced to 6.25 BTC/block and it will remain at that until 2024. The next BTC/block will be 3.125