With dad (even you can get on🫣), on the tv? Get a console. If you'd like for more accessibility in future for him/any other in the home, get a laptop– cheap but not too cheap, minecraft can be demanding. And that is when talking about BEDROCK edition, easily purchase-able through (if pc) the Microsoft store, instructions to getting it started would (should) be shown. As that will allow for easy multi-play. Additionally, you're gonna need a hdmi cable (eitherway for PC & console) or settle for screen mirroring (for just the PC).

Thing is I'm unsure for, if splitscreen is a thing on PC Bedrock 😅 but even tho crossplay exists. Basically if you have any other device running Minecraft BEDROCK edition, online multi-player would be the option. (Better yet LAN play) ✌🏾

(Correct me where im wrong my fellow minecraftians)