Short answer
In Settings > General > Tasks, the Follow-up tasks section has checkboxes to be prompted to create a follow-up task when you complete a task from a list view and when you disqualify a lead. The same page sets default due date, due time and reminder. These are personal preferences, so each user sets their own.
1. The setting
My demo portal: both prompts on, default due date in 3 business days.
2. Tip
Tasks with call or email in the title get that task type automatically.
3. Related
Task queues and an empty tasks page.