Is there a way to detect a nearby part on a certain axis?

I am going to make a script that restricts movement to the position of tiles, and the character cannot move again until the WalkToPoint (the tile's position) is reached. However, how would I be able to check if there is another tile in the direction that the player is trying to walk to?

Logic example:

if there is a tile located (5,0,0) from the current tile then
	-- Move player to tile
elseif there is a tile located (0,0,5) from the current tile instead then
	-- Move player to this tile instead
else
	wait()
end

Just assume bounds. Put all your tiles into a two dimensional table representing the grid, and then use that to check.

if grid[posx+1][posy] then -- If one to the right

elseif grid[posx][posy+1] then -- If one forwards
 -- etc
end