I also have never done any trading before. But if I want to start doing lot of trading, let say with btc but also with eth and those other coins, i should definitely get a 2nd hardware wallet for this right? I have heard of metamask and never used it ever. But I heard if you connect to bad contract or something not good, you could get hacked?
No need to use an extra hardware wallet, imo.
You won't the leaking private keys or anything like that when you make a transaction. So you can use it once a day and there is no security risk (unless you are going to care it around out of your home)
As you never day-traded before, start small.
Just send 1%-5% of your overall holdings and try to day trade it.
Keep all that money in the exchange while you are learning.
See how you feel and if you really want to keep that strategy.
Also do people who trade daily keep their coins in say uniswap, pancakeswap or those things.. do you keep the coins there or you move them to your metamask or hardware wallet daily? Seems like you would be wasting lot of money if you keep moving the coins back and forth daily if you are a trader?
Uniswap and pancake swap can be done from within your hardware wallet. You do not need to move your coins out of the hardware wallet to use them.
They are just swaps. They will interact with your metamask (compatible with trezer/ledger) and will send the coins back to the same address you sent from.