How do you make a signboard outside?

I believe you can buy 1 at Nook's store but I have Nookway, so maybe you need a better nook's store but I think it's above the house paint in Nookway. In case you don't know what I am talking about, you can get better versions of Tom Nook's store if you go there often.

Yes, the first question is right. You can only get a Nookway's buy making your first mortgage payment. Nook will announce by mail and on the bulletin board that he's closing to renovate. Then you get the next step up in his store.

Buy a sign then have it in your inventory. Select it where you want it to go and hit "Drop". Then stand in front of it and it will say "Post a picture?". If you want to, click "Yes" and it will show your designs (from the Tailor shop). If you don't have any, go make some!

Cool trick w/signs. Get THREE and you can box an animal in front of their door! Place one on each side of the door step and one in front. Do it while they're sleeping. It seems to upset some of them, so if you don't like one and want them to move, it may help.

There are various places you can't put signs, such as near rocks, or too close to buildings, or on the stones by the wishing well or town center. You also can't put them on the island or in other people's towns.