@Triathlete I would replace like-for-like with what you have, unless you’re set on changing the rest of the set. If you counted the smallest and largest cog on your cassette, then yes it’s 11-32.
It all boils down to cost for me. If you’re mostly on the trainer, there’s no real benefit to upgrading, especially if you use ERG where you can stay in the same gear for most of your training.
That said, I’d second @d_diston on the KMC chain though. I use these for MTB’ing and they are bullet proof. I’ve had a Shimano chain snap half-way through a race and it’s not nice!
Edit: If you have a local bike shop you can use - I’d highly recommend as they can talk you through, find the part and fit. A friendship with an LBS is like gold