After modeling and texturing your asset, you can begin the process of exporting your Blender project as a .fbx or .gltf. For up-to-date settings, see Export settings.
To export your model as a .fbx:
In the topbar, click File.
Select Export, then FBX (.fbx).
On the right-hand side of the file view window, change the Path Mode property to Copy, then toggle the Embed Textures button.

Set the Transform > Apply Scalings to FBX Unit Scale. If you run into scaling issues on import, see Blender FBX scaling for alternative approaches.

Click the Export FBX button.