Paris Transport

[CAH706]

Hi

Couple of transport questions for those experienced with Paris.

I’m taking my son to Paris tomorrow and we will be getting the RER into Paris from CDG airport. Once in Paris we will need to get the metro to the hotel. Will I need a separate metro ticket or does the RER ticket also cover the metro connection?

Is the metro like the London Underground and New York subway where you can use contactless cards at the entry barriers or is it ticket only? Looking online it would appear that you have to buy the tickets in advance but that seems a little outdated.

Thanks in advance for any help!