Weird shadows on mesh [solved]

Your image link points back to your post.

I looked at your mesh and without the screenshot of your problem I'm just guessing but you have geometry inside your mesh you should delete. Tab into edit mode, press 3 on your keyboard to enter face-select mode, select every visible face and press H to hide them. You'll see faces that are inside your mesh. Select and delete them, then press alt + H to unhide everything.

Also, split the edges to avoid wonky and ugly shading on your mesh.

Note that I'm using Blender 3.3 so you may find the keyboard shortcuts I suggest don't apply to you.

After deleting geometry inside your mesh, press A to select everything then M > By Distance to remove all of your doubles (vertices sitting on top of other vertices). If you're in solid viewport shading you will immediately see the weird shading on your mesh.

Once you've removed doubles, press 2 on your keyboard to enter edge-select mode, then hold shift and select all of the edges on your mesh that you want to appear sharp. Edge > mark sharp. The edges should turn blue. Object mode. Then apply an edge split modifier. Be sure to uncheck "edge angle" before applying the modifier.