Hello, here is a list of the errors I found in your levels and what could worked on. Hope this helps.
Your inside levels
* I found that your floor designs were quite forced(shown best in the last picture). Floor designs should seem nature and look pleasant to the eye.
* This goes the same with your levels walls. There is no need for your walls to twist and turn that much within a room. Instead, I suggest to keep your walls and level layouts more simplified.
* In picture 4, a door is missing a borders.
* In picture 4 as well, the stair case could use a borders. The white line should be found on the outside part of the wall facing the stairs-case.
* in picture 2, the small table should be moved down one tile. When placing a table against the bottom of a wall, the legs of the table should never show.
Overall, I found that your inside levels aren't half bad. Your levels layouts are interesting, but could use less jagged and complex wall structure. After obtaining more graphics, your levels will look much nicer. Just scan era pc's levels to obtain graphics.
Your outside levels
* In picture 1, the three tiles you use do not flow well together. Try and find a way to make them all flow. This could be done by rearranging those tiles or using a different tile perhaps and switching it out with a current tile.
* In picture 1 as well, you should not use the tile you are using as a pathway leading away from your house. I suggest using the sidewalk tiles.
* In picture 5, the building could be more symmetrical. both sides of the building should match. (I do not suggest this will all buildings)
* both levels could use door boarders.
* the roof in picture 5 is missing the corner tiles that connect the rest of the pieces together.
Overall, i found that the first building isn't the most aesthetically pleasing. This can be changed by playing around with the current tiles and rearranging them into a better layout. The second building is actually quite interesting. After a few minor changes the building could look pretty nice. Keep up the good work.

You have lots of potential, and after making a few changes, you will see huge improvements!