The Upcoming Free Agents screen (League Menu >> Transactions section >> All Free Agents >> Upcoming Free Agents tab) lists all players who are scheduled to become free agents at the end of the current season:

This screen projects which players will reach free agency at the end of the season. You can use this as you plan out your offseason moves. Will it be a good crop of free agents? Can you get some value in return at the trade deadline for your pending free agent slugger? Note that teams may make transactions (such as sending a player to the minor leagues) that can affect their service time, and thereby whether or not they reach free agency. This screen is only accurate as of the moment you view it. Do not assume that a player on this list will be available for you to sign at the end of the season! Teams can and will re-sign players to extensions before they reach free agency!

This screen is only relevant if you have free agency enabled. See Offering Contracts and After the Offer for more information on the contract offer process.

On this page, you can take advantage of OOTP's Views, Filters, and many of the Common Drop-Downs and Common Action Menus. Review those sections to get a better understanding of how to manipulate the data on this screen to suit your needs.