Dear forum

I weight 180 pounds and am 5' 10'' in height,
Browising on my local marketplace I found this extremely well maintened scott road bike that goes fairly cheap, with a Medium sized frame and 26 inch wheels.
My question is how much of a problem would the wheels cause me since I know the recommended size for road bikes is usually 27,5" , 28" or even 29".
The frame size I think will not be much of a problem. Is it normal for road bikes with 26" wheels? Also if I have enough space within the frame am I able to change the smaller wheels for 27,5 or even 28"?

Thanks in advance