Hi I am not familiar with qb and don’t understand how to keep track of expense invoice etc

Welcome to Community, veli-sk-hotmail-. 

I'm here to guide you on how to track expenses in the invoice in QuickBooks Online. 

To begin, we'll have to turn on billable expense tracking. Here's how:

1. Click the Gear icon.
2. Select Account and Settings.
3. On the Expenses tab, select Edit from the Bills and expenses section.
4. Select the necessary information.
5. Click Save, then Done.

After that, here’s how to bill a customer for an expense.

1. Go to the + New icon.
2. Select the transaction (Bill, Expense, or Check) you want to create.
3. Select the name of the payee. 
4. Click + Add new if you haven't added it yet.
5. In the Category column, select the expense account for the transaction.
6. Enter the description and amount of the expense, then place a checkmark in the Billable checkbox.
7. In the Customer column, select the customer you want to bill for this expense.
8. Select Save and close.

Then, link it to the customer's invoice for reimbursement. Here's how:

1. Select + New then select Invoice.
2. In the Customer dropdown menu, select the customer you created a billable expense for.  This opens the Add to invoice window.
3. Select Add on the billable expense you want to charge to your customer.
4. Select Save and close. 

Once your customer pays, you can record the invoice payment in QuickBooks. 

Meanwhile, QuickBooks Online offers instructional materials and tutorials to make navigating even easier for beginners. You can find our training videos, webinars, and articles through the following links: 

• Video Tutorials for QuickBooks Online
•  Getting Started for QBO
• Bookkeeping Workflow Tips

We're just around the corner here to help you again if you need anything else. Just reply below or post new questions and we'll be glad to answer them for you