Fees are how much you want to charge a brand for creating a piece of content. The budget range that you see on a campaign is the actual compensation that the brand would be willing to compensate you if they move forward. It is recommended that you bid within this price range to help you better your chance at securing the sponsorship, but it is not required. Remember to always bid appropriately to your channel size.
The proposal deadline is the last day that the brand will accept new proposal submissions. If you’re interested in that campaign get that proposal in before it expires.
The Delivery Date is the date that you are committing to complete creating the content you have proposed to the brand. This date can shift depending on when the brand gets you the product. Always work with the brand to find a date that works for both parties.
For more details on Expiry Dates view this article.