Can I view a few companies in a dashboard at the side so I can open two or more at the same time on two separate screens and work on both at the same time?

It's an honor to address your question for today, finance-osulliva.

In QuickBooks Online (QBO), you can only open/switch to one company at a time and open multiple windows in the same company you're working on. You may need other device to open different companies at the same time.

To learn more about managing multiple companies, check out the following link. It has a bunch of useful information for you and your business: Managing your companies. 

Be sure to let me know if you have concerns while working in QBO. I'm here to lend a helping hand. Have a good one.

@finance-osulliva 

Open one account on the primary browser and the other one on the incognito/private browser. If you can run 3 browsers on your machine, you will be able to open up to 6 QBO accounts at the same time.