I want to load End Date field as start date field +2 years when user enter start date. this is a new form of my list.
This requirement can be handle using
Content Editor WebPart or
Script Editor WebPart.
You can edit the
NewForm.aspx and add the
CEWP/SEWP and handle the change event for the
StartDate control. And based on this you can manage your
Similar post is shown Auto-Populate the Field Values Based on Text Change in SharePoint Online List Forms.
and use a Calculated Field
=DATE(YEAR([Start Date])+2,MONTH([Start Date]),DAY([Start Date]))