We have a steam group with the most active chat room of any steam group ive ever seen, usually there is some knowledgeable in there who may be able to help you out with TF2 specific problems. http://steamcommunity.com/groups/TF2Mappers
Last but not least once you have a good alpha or beta map you need to get playtested, be sure to check out the Map Testing Gamedays, we try to run one every week, great way to relax and find bugs with your fellow mappers. http://forums.tf2maps.net/forumdisplay.php?f=35
If this is your first time logging in after the migration (Feb 8, 2022), you must reset your password to log in. Follow this guide if you're having trouble