She's jsut looking for comfort - your breasts are well designed to give it She's so little she probably is getting the hang of day and night still. It just takes time for them to settle into things. If you can, getting outside in the daylight during the day can help, as will keeping things dark adn quiet at night.

You can try a dummy if you want to, it's really up to you. There is a risk of nipple confusion which can lead to problems attaching to the breast - just be aware that it's a possibility.

The other thing is they do normally spend a lot of time at the breast feeding and comfort sucking, especially in the early weeks adn this is both totally normal and beneficial both for your baby (there are important emotional/pyschological benefits) but also for the establishment of your milk supply. Sometimes using a dummy can interfere with this process. Again, just something to be aware of.

In the early weeks it's all just trial and error as you find your way. One day one thing works, the next it's something else. It's ok, that's how you get to know your baby and learn how best to mother them.