i am new on ebay and sold my 1st item the winner did not pay me so wen i have done a unpaid item. she has give me a red mark so webaywont re

You need to go in and close the unpaid item case as it's over four days now.

Once you've closed the unpaid item case the buyer gets an unpaid item strike on their account, you get your final value fee back (the 10% that eBay take) and can relist your item.

You also need to contact eBay regarding the negative as they will remove that on closure of the unpaid item case.

You can probably get the feedback removed, as has been said. If all else fails you can just start again with a new user account. As a new member you have no feedback to lose.

Don't let it get you down. You will find that the majority of users are decent - you've just been very unlucky with your first sale. Apart from your own problems with her she is one of those dreadful buyers who never leaves feedback for a seller unless it's to give a negative!