I removed the navigation bar and links from the top of this form ( need to go to all user to fill in) Would anyone please let me know how can I move the form itself in the page? I want to remove extra space on the page.
Site Settings > Tree View > (check the box for Quick Launch or Tree View) to enable the left navigation again.
The screen shot looks like you have an "InfoPath Form" for that list. This is a advanced form editor for SharePoint. If you have no unique customizations that you know of on that form in regards to formatting, rules, conditional logic etc. it would be best to stick with the standard form fields.
To reset things back to the normal form fields that SharePoint generates do the following. List Settings > Form Settings > Select: Use the default SharePoint form > OK
Then go back and take a look at your form as it should be left aligned without the white space. (Also you will see the default save and cancel buttons)