How can I some areas with the black?

[aljustiet]

I tried to add the black color in the “Open Other” menu. But I don’t know how to crop it so it matches only some areas.

[brian]

Put your other clips on a lower track. Add your black clip to a higher track. Then, apply the Size Position and Rotate filter to the black clip.

[aljustiet]

How can I resize it without keeping the aspect ratio?

[aljustiet]

Can I “draw” with the brush on the video track?

[MusicalBox]

@aljustiet

How can I resize it without keeping the aspect ratio

You can use the Crop: Rectangle filter instead. Or the Mask: Simple Shape filter.

They both allow to make the rectangle any ratio you want.

If you use the Crop: Rectangle filter, don’t forget to make the Padding transparent.
If you use the Mask: Simple Shape you’ll probably want to reduce Softness to zero.

If you prefer to use the Size, Position & Rotate filter, you can change the Size Mode setting to Distort (instead of Fill)