How do I create a solo? [Discussion] [play]

I have been playing guitar for a couple years, mostly acoustic and some finger picking. My brother and I want to create a solo for Rivers and Roads by The Head And The Heart. We play it in the key of C. I am looking to just make something very relaxed, laid back, maybe almost bluesy.

From looking around, there are a lot of different scales and I understand that each will have a different feel and sound. Just maybe looking to get others ideas and thoughts and how you would go about doing it.

Thanks