How do I build a inside wood heater?

Burning wood inside without a chimney is a dangerous idea. Can be a fire hazard. Smoke, soot, and carbon monoxide can hurt even kill you.

Have you checked with your home owners insurance? If a stove isn't certified they may not cover you or even cancel your policy. In some areas it is illegal to install an wood stove that isn't certified.

Not sure what on earth a 13 brick "wood heater" is. Do you have a photo you can post to show us what you're talking about/have in mind? As for the idea of installing a wood burner inside your home - consider the comments above, and also at a minimum you would have to have outside venting and meet all code requirements. In some places having a wood-burning indoor stove or installing a wood-burning fireplace is illegal.

I have a 3 brick propane wall heater

You need to invest in Electric Heat until you have enough cash to install one professionally. There are so many codes against DIY including Fire Safety and Carbon Monoxide Emissions, as pertaining Wood Burning Indoors, this is one job that really should not recommend to DIY to anyone without experience in Masonry.

You can build a Firepit outdoors easily with bricks:

8 at the base

8 at layer 2 offset them 4 inches

7 at layer 3

6 at layer 4

5 at layer 5

4 at Layer 6

And from that experience with 38 bricks you should see how easy it is to make a Brick oven with a Smokestack out of fewer than 200 bricks. Bug also understand that this is not something you want indoors in your living room smoking everything up and getting soot everywhere.