Hello,
I am researching ways how to trace transactions and hot and cold wallets of exchanges, gambling sites, cantors, mixer.s What sources of data could I use? What algorithms and scripts would be useful to do this? Maybe, do you have some interesting articles about this issue? Any help would be great

Apart from the research/documentation ETFbitcoin has already posted, there are a couple sites which let you track outputs from certain exchanges and other sites. If you just want to track/ try to identify a couple adresses, you could perhaps try these sites..
See,
https://www.walletexplorer.com/, and for things such as coinbase/binance, ive used
https://matbea.net/ in the past.
(Matbea seems a bit clunky, but it actually is pretty decent and i think it might even be better than walletexplorer.)
Its been a while since ive actually looked into this, so im also kind of curious if there are any better (free) apis or just sites/explorers to identify transactions coming from certain sites than the ones i already mentioned.