How to use Manager in construction field?
Start with modules you know you need such as Bank accounts, Customers, Sales invoices, Suppliers, Purchase invoices etc. This will cover your basic needs to track money, accounts receivable and accounts payable.
If you want to issue quotes/estimates to your customers, enable Sales quotes. If you need to prepare purchase orders for suppliers, enable Purchase Orders.
If you have employees, you can enable Employees and Payslips. If you or your staff pay expenses out of pocket instead of using company funds, enable Expense claims… if you want to track profitability by projects, you can enable Tracking codes
Start simple and keep enabling modules as you need them. Better look at the guide at Guides | Manager to explain how to use individual tabs, reports and other options in more detail.