best invoicing solution?

I am doing very small business and I don't actually need a very systematic
invoice. However, I have a plan to start to be a little bit more systematic in the coming new year

Is there any free or low priced excel template, windows software or apps where it can let me have a better management of my customers and invoice?

I often need to create invoice for my customers but currently I only use simple word and create tables by myself, which is very low tech and not organized.

For example, I hope I can find out all the historical invoices sorted by a particular customer, I can assign code for my stocked items, many of
my customers only pay part of the money because I can't deliver my
products to them immediately, so I want to have an auto calculation
and list of how much I've received this month (and wish I can also sort them by their means of payment so that I have a better tracking) and how much my customers will have to pay to me (outstanding amount in total)

Any recommended solution? I have NO excel knowledge....
Since my invoice will contain the personal information of my customers, I hope it's an offline and reliable solution

Thanks for advice.

bro67 said:

For tax purposes, you are best to use a known solution such as Quickbooks. Excel is a spreadsheet, not a invoicing/bookkeeping solution.

thanks you