Something I should worry about?
 

Just bought this Dendrobium from a nursery last week. It seems very healthy but just started to get spots on two of its leaves. I have removed the leaves but I’m not sure if this is just an environment shock or if this is an infection. It’s the circles on the leaves that are freaking me out a little. Any suggestions would be appreciated.

You're going to lose older leaves. That's a lower leaf too. Mine do much the same thing. I fretted at first, and sprayed and fussed, to no avail. If it spreads, take action but, I doubt it will.

I agree with Dollythehun that it is probably not an issue. It wouldn't hurt to remove the affected leaf with a sterilized tool just in case, but I doubt it is a problem.

More and more leaves are falling from this orchid and it’s not just the lower leaves. Is this still normal or should I be worried? I think probably 6 leaves in total.

I'm not sure if that is a nobile type dendrobium but if it is that's normal behaviout.

It's not a nobile hybrid.

Dens can be pretty fussy and drop leaves if the growing conditions change. I agree with Dolly - don't fret.