In this day and age, finding the right frequency is easy with most walkie talkies. Channels 1–7 are GMRS, 8–14 are FRS, and 15–22 are GMRS again. This has been standardized, though you can still find the occasional non-standard holdout. In that case, you’ll need to look up the FCC frequency standards for the channel to which you want to connect and compare them to your radio’s user manual. You’ll be able to connect to the right channel.