Having a tough time getting good comps

[Junior Salters]

Hey guys, I'm having a tough time getting comps for leads. I'm currently stuck using sites likes Zillow to see what houses that are similar in size and layout have sold for, but I'm not sure how accurate these numbers are due to how easily accessible they are. Do I definitely need a real estate agent's help on this one or are there other ways? OPEN TO ANY SUGGESTIONS!!!