Can I walk to yuexiu park from guangzhou airport and how far/long is it?

I'm afraid that it is a long distance for you. :)
This park is about 19 miles away from the airport.

You can take the subway to get to the park.
It will take no more than 40mins on the way. So after arriving, you have enough time to appreciate the beautiful scenery of the park.

You needn't a visa. But you should apply Stay Permit in the airport.