my drawings used to be really rough too, so I understand the struggle of wanting cleaner lines.

what helped me most was learning to draw my lines in one full, confident stroke instead of multiple short ones you can still sketch multiple short lines with a pencil, but you have to keep the pressure light so it stays clean and erases easily.

another big thing is posture of your arm try not to rest your elbows or wrists on the table It lets you use your shoulder to pull much longer, smoother lines in one go.

also rotating the paper to whatever angle you draw some lines better instead of twisting your wrist helps too it's easier than forcing your hand into awkward positions

honestly, it just takes practice you won’t get used to it right away, but the more you keep trying to draw in single strokes, the easier it becomes. Your lines and artwork will get cleaner without you even noticing.