8 Month Old Kitten Urinating on Furniture .. HELP??!!

[Bentley2015]

PLEASE HELP. I am new to this, this is my first kitten. I have an 8 month old red Maine Coon. Over the past 3 days he has been urinating on my couch. He is using the litter box as well. A week or so ago he was urinating on my bed and has now moved to the couch. I had him checked at the vet and he was put on an antibiotic 2 weeks ago for inflammatory but no UTI was found in his test results. I bought Nature's Miracle Stain and Odor remover with the repellant in it. I sprayed this all over the couch and he still urinated on it. I don't know what else to do. If any one has advice, it is greatly appreciated.

Thank you !