Most modern TVs do indeed still have a traditional arial input, as they include a digital TV receiver - they will still read an analogue speccy input fine I would have thought.
You can get a cheap cassette player off ebay that will do the job - you can reacquaint yourself with fumbling with a jewellers screwdriver to adjust the azimuth on the head
It will also be great fun - old home computers are the perfect way for todays kids to learn programming skills, as they are super simple and don't include the distraction of Internet connectivity. My 2 year old will be inheriting my BBC Model B once he's old enough - I learned to code on it at 12 and it's given me a career worth of skills
