Quickbooks clean up an set up

I have used the US version of quickbooks for some years and I only us it for invoicing. I set it up the best way I could when I started but I do not this its works well and I'd like my experience of it improved.

I do not need an accountant or any tax preparation

I have 1482 contacts but I think some are duplicated and I need the duplicates removed

• Contact duplication identification and cleanup
• Return invoice setup and handling
• Invoice template review and configuration
• Accounts Receivable follow-up research and recommendations
• Charge and billing automation research and recommendations