Just about to start investing today. Do I open a cash ISA or stocks and shares ISA?

Can I open both, is there any point in that? What’s your recommendation and advice on the ISAs and maybe any efts if S&S isa? I earn about 1300 a month but only use 250 for transport. (19 years old). How much would you advise to spend a month? I know it’s a lot of questions but I’d appreciate any help.

Thank you