Why does the error say ServerScriptService.Script:28: attempt to index nil with 'Name' ?

Im trying to make a simulator game with a pet shop. Ive never really coded before so i looked up a video for the pet shop. Im doing everything correct but this line wont work. here is the whole line: (first line is the line with error)

if not player.Pets:FindFirstChild(MainPet.Name) then if player.leaderstats[currency].Value >= MainPet.Price.Value then player.leaderstats[currency].Value = player.leaderstats[currency].Value - MainPet.Price.Value local clonedPet = MainPet:Clone() clonedPet.Parent = player.Character clonedPet:SetPrimaryPartCFrame(player.Character.Head.CFrame)

If you know anything about scripting and you may know the issue plz lmk.