How to get more storage on sdcard?

I am running out of storage on my sdcard and my phone gives me this information:

1. Are these the backups of TWRP, that use so much storage?


2. Why is clockworkmod still there using so much space? I flashed TWRP after using clockwork since I learnt, that TWRP is more recent and up to date. can I delete clockwork folders?


3. cmupdater: again, are these the downloaded zip nightlies? I should right now just have 3 zip files.

Thank you very much for your answers.