Bought a new oncidium, is it sick?

[Lamia189]

Hi guys!
I was at my local depot today and for the first time ever I found an oncidium for sale, so of course I bought it. I don't usually mind buying plants that don't look their best, having the mindset that nursing them back to health and seeing them flourish is more rewarding to me. It is my very first oncidium, so I could do with some advice.
I have found a few brown spots on the orchid, however I have read that its quite common and nothing to worry about. But seeing a huge variety in those spots online made me wonder if these are actually the ones or something else? I have also noticed that majority of them are on one side as shown in the pictures, also the leaves seem to have some lighter green patches as well. So could this be a sunburn or?
So, my question is, is the orchid ok? Can I place it with my other orchids or would that be risky? If it's a pest disease I wouldn't want it to spread. Thanks alot!