“Cash account” – what & where?

Hey there fam,
I'm learning at the moment and I know there's a CFD account type with a default leverage, meaning I'll have to sell/buy everyday unless I want to pay overnight fees. The opposite to that is what interests me, DCA and buy stocks/etfs. I know there's IRA but it's a long term investment for retirement.

If you would enlighten me with your experience & knowledge it would be much appreciated: what's the best option for 3-5 year term?

Thanks in advance!