Following Script

local Humanoid = script.Parent.Humanoid
local PrimaryPart = script.Parent.PrimaryPart

local FollowDistance = 15

function GetNearestPlayer()
    local Pos, Distance = nil,math.huge
    for i,v in pairs(game.Players:GetPlayers()) do
        if not v or not v.Character or not v.Character.PrimaryPart then continue end
        local DistanceFromCharacter = (PrimaryPart.Position-v.Character.PrimaryPart.Position).magnitude
        if DistanceFromCharacter <= FollowDistance and DistanceFromCharacter < Distance then
            Pos = v.Character.PrimaryPart.Position
        end
    end
    return Pos
end

while wait() do
    local Pos = GetNearestPlayer()
    local DP = game.Workspace.Dummypoint.Position
    if Pos then
        Humanoid:MoveTo(Pos)
    else
        Humanoid:MoveTo(DP)
    end
end