Mousefolk character has a number of traits in common with all other Mousefolk.

Furry, nimble, small, retiring and agreeable race.
Ability Score Increase. Your Dexterity score increases by 2.
Age. A mousefolk reaches adulthood at the age of 5 and lives to be about 40 years old.
Alignment. Most mousefolk are neutral and tend towards good. They try to keep the conflicts of the other races at arm's length, but display remarkable ferocity when their friends, families, or communities are threatened. A reverence for nature and life is close to the heart of mousefolk, and they are loath to take a life if it can be avoided. They prefer to live quiet and unassuming lives, giving honest work for honest pay.
Size. Mousefolk grow between 2 and 2 1/2 feet tall and weight about 25 pounds. Your size is Small.
Speed. Your base land speed is 25 feet.
Darkvision. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.
Keen Senses. You have proficiency in the Perception skill.
Mousefolk Weapon Training. You have proficiency with the rapier, shortsword, shortbow, and handaxe.
Nimble Dodge. When attacked by an attack of opportunity, you may use your reaction to impose disadvantage on that attack.
Languages. You can speak, read, and write Common and Squeak Speak. Squeak Speak can be used to speak with other rodents and uses the Sylvan script. Mousefolk place great value on the written accounts of their legends and histories and encourage everyone to keep journals and records of their deeds. Almost all Mousefolk speak Common to converse with the people on whose lands they dwell or through which they are traveling.
Subrace. The two main kinds of Mousefolk, Softpaw and Meadowgard, are more like closely related families than true subraces. Choose one of these subraces.
Softpaw

Ability Score Increase. Your Intelligence score increases by 1
Artistry. You gain proficiency with one type of artisan's tools or one musical instrument.
Squirm. You can move through Tiny sized spaces.
Meadowgard

Ability Score Increase. Your Wisdom score increases by 1
Brave. You have advantage on saving throws against being frightened.
Speak With Small Beasts. Through sounds and gestures, you can communicate simple ideas with Small or smaller beasts.