1. Goto https://drive.google.com/settings/storage
2. Click at View detail under Pie chart.
2.1 To reclaim space in Gmail, go to https://www.gmail.com, delete some emails and remove from trash.
2.2 To reclaim space in Drive, go to https://drive.google.com, delete some files and remove from trash.
2.3 To reclaim space in Photos, go to https://photos.google.com, delete some photos and remove from trash.
3. You should get the space back within 24 hours.
Also, please see this help page for more info- > Clear Google Drive space & increase storage