Not completely sure what you want to achieve. Will you be playing YouTube or YouTube music? Or play your own music? From what source?

If it’s “just” for music, I wouldn’t recommend a “Beam and satellite speakers” - that setup is more suited to tv or movie input and home theatre. 
 

Instead, get a pair of matched speakers. Sonos’ own view is that two Fives is best for pure stereo, but two Eras are a close second and will also give you Spatial Audio from a suitable source. Era 100’s is the more budget option. All options are compatible with Airplay. 
 

With my Era 300 pair, I will sometimes view a video clip  on my iPhone but send the audio to the speakers for better audio than the phone can provide. 

Yes, I just want to listen to the tv and if I want to listen to a song on YouTube, rather than play it on my phone, I’d like to play it through the beam so it will also play through my 2 play1 speakers? Anything is better than my phone speaker 

I’m not sure you’ll get sound from the Play:1’s if you bond them as surrounds, because the Beam/Play:1 combination will be playing a DD 2.0 or stereo signal - ie no surround data.
 

You could get any Airplay-compatible speaker, group your play:1’s with that and get the sound through your ’1s ? 

Ah… so I don’t need a beam? Sorry… feel so stupid. I’m a musician and use lots of pa but never had a decent sound on my tv or own a music system. I use my phone for everything  and when I’m transcribing music on the piano, I play YouTube one my phone as I listen and write down what I hear. My phone won’t send youthful to my play ones, it plays Sonos radio and I don’t want that. I just want to be able to hear what I choose through my play 1’s? So what do you suggest if a beam won’t allow it? 

You only need a Beam if you want better sound from your TV. If you would add the Play 1’s as surrounds to the Beam they would, as described above, not make a sound because YouTube is a stereo source. Because your Play 1’s are an older design you can’t Airplay to your Play 1’s. Since they can be grouped with newer speakers, the cheapest option would be to buy an IKEA Symfonisk, Airplay to that from your phone after you’ve grouped it with the Play 1’s.