I have a dirt bike thats been sitting in a garage for like a year what should i do?

[Zach B]

i have a dirt bike that's been sitting in a garage for about a year what should i do? it already has gas and oil but it been siting there awhile do i need to change out the gas and oil? i was told the only thing wrong with it was the spark plug so i bought new one i changed it and the bike started after a couple trys but is started to drip oil from some where not sure where thou but ill find out tomarrow what would cause oil to leak is it a old cracked gasket or something like that from sitting in a garage collecting dust for awile? its like a young adult suzuki bike