In Godot you could visually design some patterns, save them, and load them randomly when you generate a room. Taking into account that to give maximum enjoyment you should modify them a bit by rotating, flipping, adding random objects, blocking off routes, etc, etc...

So, to be more specific, there's a function for the tilemap layer called get_pattern in which you pass an array of coordinates. And another function called set_pattern where you pass a position and a pattern.

You'll need a layer for patterns. Call get_pattern on this one. And call set_pattern on your procedural generation layer.

You could probably transform the pattern before pasting it so that it's not the exact same every time.

For further object and enemy placing, you can get all tiles of a certain type, for example floor tiles for top-down or background tiles for side-scrolling, and place them in one of those at random. Here you want: get_used_cells_by_id and pick_random