Frey sat on Odin's throne when he was gone. He saw Gerda, a giantess, so he called his servant to ask her to marry him. The servant convinced Gerda to marry Frey.
Since Balder was immune to all things except mistletoe, Jealous Loki tricked Blind Hod into shooting an arrow with the plant into Balder's heart.
Freya, the goddess of love and beauty, had a beautiful necklace that made Loki want to steal it. Loki stole Freya's necklace in her sleep as a fly, and Heimdall saved it from him, turning into a seal to fight Loki.