When you add a block to the site, you can adjust it through the Block Settings:
It may happen that while you were editing the block you realize that it doesn’t go well with the site. In this case, you can choose another one by clicking on Add Block:
Keep in mind that you don’t necessarily have to add a block from a particular section. Browse through all the blocks offered and choose one which suits you best. Remember that you can change block’s content and image according to your needs.