Yes, incisions are necessary to perform the liposuction procedure and these will leave scars. However, they are generally short and are placed in discreet locations.
I generally advise patients wear their garment 24 hours a day for three weeks, removing it only when bathing or washing it. From 3 to 6 weeks, wear your garment in the day only. It helps with easing swelling and reducing the risk of seroma. The garment should fit snugly but not to the point that you can't breathe or are feeling sore. It's best to follow your PS's advice or express your concerns directly to them so that they may respond.
The final result of liposuction can usually be assessed at 3-4 months.