After extruding I get this type edges. But I want the old edge loop to be at the same place as it were. But when I extrude this the old loop gets messed up and also changes the position and a new loop is generated at the place of the old one. So I want both(the one before extrude and the one after extrude) the loops to be at the same place. What shall I do to fix this? This is the link to video I am watching to learn:-https://youtu.be/zwf86kHwNoE timestamp:- 6:35 [Video is from Blender Arts channel.]
You have inconsistent Normals:
- Display with Overlays > 'Face Orientation'
- Flip with AltN 'Recalculate' 'Inside' or 'Outside'.. whichever takes you to all blue, viewed from the front.
I quite like to tweak a modelling copy of my ( Edit > Preferences > Theme > 3D Viewport ) to something akin to this:
.. which means it's comfortable to leave the 'Face Orientation' overlay on all the time. Then you always know which way your faces are pointing.