To create a poll, first you need to create a topic. Then choose pool settings in the right action menu.
You can add poll variants using +Add new variant button 
Also you able to set additional settings for your poll, use checkboxes to turn on required ones. 
Find out poll example below.
How to put poll on dashboard?
1. Open your account settings interface.
2. Choose Dashboard layout section and then required forum.
3. Click on the Add module left button
4. Choose Poll module from the list of the available modules.
5. In the module settings popup choose, which poll to display from the dropdown menu .
6. Click Save 
Now you have poll module on the dashboard, you can set it position as usual.