Grizzly 660 started once and wont start now.

Inherited a Yamaha Grizzly 660, no owners manual ect, started the first time and a few times afterwards, acted like the battery was running down. ran for about 10-15 seconds and then died, would barely idle. replaced battery with a new one fully charged. The new battery would turn over and start a few times but also acted like the battery was dying but still "clicks"

It had been sitting for about 3 years inside of a garage, has some mouse damage but wiring is intact. I cleaned connections and checked wiring ect.
It clicks when attempting to button start, our mechanic (without seeing the grizz himself said it would be dirty connections).
I see a lot about Solenoid and Starter replacement advice here but considering it did start the first time I wonder if anyone has some advice for me that I could try before replacing these items.
Not very experienced with this but interested in getting some education. I figure while I wait for a reply I will download the users manual and gather more information.

-thanks for reading and your time here!