How to make hand-drawn logo into vector diagram with AI?

2. Analyze what graphic signs can be composed.

3. Draw the required shape, copy the same circle directly, and draw several auxiliary lines (I used three perfect circles, one ellipse and three rectangles) (save).

4. The house and the door only have strokes, but there is no fill color. The strokes are round (provincial).

5. Select All, Object Menu-Extended Appearance

6. Select All, use the Path Finder, the first button, and merge shapes (save).

7. You can see that many places are round.

Select the anchor point that needs fillet.

Drag these circles to pull out rounded corners (Save)

accomplish