Starting July 30th, you will no longer be able to log in to a Curse account that was not merged with a Twitch account. If you have not yet merged your Curse account with a Twitch account, please do so here! Otherwise, your account and its content will be inaccessible.
If you are looking to join a server, you can post applications to threads in the Servers forum section. We are no longer going to permit individual "looking for" threads in the Minecraft: Java Edition discussion forum sections.