Im building a wall ive already had tear it down once and this time I double checked to makw sure the post was stright and it in the right spot but i cant build gate....pls help!!!!
You likely builded it a pixel off, no easy way to fix that. You can do it as Trungdle said, build a corner, then two normal sigments and then another corner. If you did that, destroy the two middle sigments.
One cornerpost, extend it with 2 wall sections,right lick build another cornerpost connected to those, tear down the wall sections and right click build gate