I'll be in Paris for one full day in June. I fly in to CDG and will arrive early in the morning. My plan is to take the RER to my Airbnb, drop off my bag and go exploring. I don't have the details of exploration down, but I was hoping to be able to have the option to hop on the Metro or a bus if I wanted. The next morning, I'll be taking the RER from my Airbnb to Gare de Lyon to catch a train. I downloaded the RATP app, and I'm confused by the ticket options on it. There are Navigo Day, Weekly, and Monthly options. Can I just buy a Day Pass on the app without needing a physical card? There's also "One-way Ticket t+" listed twice. They each have the same description, but the first is priced at 14,90 and the second at 1,90. The second one is obviously a single ticket. Is the 14,90 meant to be the new version of the carnet?
Thank you in advance for any help offered!