It seems you're asking about events and details from the medieval English poem "Sir Gawain and the Green Knight." Here are the answers to your questions:
3. The Green Knight did not harm Gawain with the first two "feigned" (pretend) strikes with the ax as part of a game or test. The Green Knight had proposed a beheading game, where he would strike Gawain once and then allow Gawain to return the blow in a year's time. The first two strikes were merely tests of Gawain's courage and integrity. The third time, the Green Knight drew blood to remind Gawain of his obligation to meet him a year later for the final blow.
4. Gawain admits to two vices, which he calls "the destruction of virtue." These vices are cowardice and covetousness. He committed these vices by accepting the green girdle (or sash) from Lady Bertilak, which he believed would protect him from harm. This act showed cowardice because he valued his own life over his honesty and integrity, and covetousness because he coveted the protective power of the girdle.
5. Gawain refuses the invitation to return to the Green Knight's castle to meet the women because he feels ashamed of his own actions and believes he has failed in his quest for perfection. He says that he does not blame himself for being misled by a woman because he believes that all people, including knights, are prone to human weaknesses and can be deceived. His refusal to meet the women reflects his sense of guilt and humility in the face of his own imperfections.