There are multiple ways to delete a task in Float.
From the task menu
Click Actions > Delete to remove the selected task.
From the project menu
Select the Tasks tab, find the task you want to delete, and click the "X" icon to confirm. This will delete all instances of that task from the Schedule.
From the Schedule
Right-click anywhere to bring up the bulk actions menu, select Delete, and then blast your unwanted tasks into oblivion.
💡 Here's a tip: If you've accidentally moved, added, updated, or deleted a task from the Schedule, you can undo the last action/s using Ctrl-Z (PC) or Command-Z (Mac). Undo is not supported for replace actions.