When shifting the deadlines of the current plan, the Gantt Chart with tracking will display the shift of blue and red segments relative to gray. Variances in numbers can be seen in the Variance table (Start Variance, Finish Variance columns), Work (Work Variance column), Cost (Cost Variance column).
To save the following baseline plans, you need to:
First, save the data of the previous baseline plan in a backup (Baseline1, Baseline2, etc.). To do this, execute the command Project - Set Baseline - Set Baseline. In the Set Baseline dialog box, select Set interim plan, then in the Copy: field select Baseline, in the Into field - Baseline1 (in the future Baseline2, etc.) and click OK: