trouble connecting Turbotax with Coinbase. My 2024 gain/loss was negative so do I need to worry about filing this?

you can input the 1099-B manually if the import is not working.  if you had a loss you should absolutely be including it will offset other gains or ordinary income up to a limit and then you can carryover the rest, and reduce your taxes.

just to add not all banks/brokerages have finalized 1099s or the ability to import so you may just need to wait if you don't want to put it in manually.  The official date for 1099-B import availability is Feb 15, see 

https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/able-import-1099/L8SGHd22j_US_en_US?uid=m6dyghqp