How do I make a pathfinding NPC that will follow a player smartly?

First we need to find the nearest person.

Example:

local vecPoint = workspace.NPC.Humanoid.Position
local closestPlayer, smallestMagnitude = nil,math.huge

for _, player in pairs(game.Players:GetPlayers()) do
     local distance = player:DistanceFromCharacter(vecPoint)
     if distance < smallestMagnitude then
          smallestMagnitude = distance
          closestPlayer = player
     end
end

Boom, we did it. Now we want the player to go the Player.

Script Example:

NPC.Humanoid:MoveTo(player.Character.Humanoid)

Final script:

game.Players.PlayerAdded:connect(function(player)
    player.CharacterAdded:connect(function(character)
if character then
local function movetonpc()
local vecPoint = workspace.NPC.Humanoid.Position
local closestPlayer, smallestMagnitude = nil,math.huge

for _, player in pairs(game.Players:GetPlayers()) do
     local distance = player:DistanceFromCharacter(vecPoint)
     if distance < smallestMagnitude then
          smallestMagnitude = distance
          closestPlayer = player

NPC.Humanoid:MoveTo(player.Character.Humanoid)
     end
end
end
while wait(.01) do
 movetonpc()
end
end
end)
end)