Self assessment registration

I made a mistake when registering for self assessment tax. The error is in the enetered as the date the business started. Would I be able to correct this? I cant even find the form on my account as I just registered few hours ago.

Hi,
You are able to amend a tax return after you have filed it.
You can find out more information on how to do this here:
Self Assessment tax returns: If you need to change your return
Thank you.