Design set of PDF or Excel documents + modify existing one

General information for the business: Welding and fabrication bussiness
Kind of support: Balance Sheet, Bookkeeping, Cash Flow, Invoicing, Tax
Description of support work: Hello, i do not have accounting software and i do not think it will be good as business is very small and i do not have time to learn complex thing.
I need set of documents that i can operate in simple way and know what happening in my business.
I have PDF invoice that i would like to be able to add VAT automatically to the total amount in invoice. If possible i would also like to have Excel document where i could input all income figures, all expenses figures and it will makes totals for me. This document will need to be made of 13 sheets (one per each month and one additional that will be automatically populated with monthly totals and generate totals per year.)
I also need document probably Excel to keep a records of my stock material so i can know how much things i have and it will notify me when stock is low. The way i see this document working the very first sheet will display all statuses and balances and all subsequence sheets will be dedicated to various stock items. They will be named like ,,Carbon Steel,, ,,Stainless Steel,, ,,Aluminium,, ,,Power Tools,, ,,Office Equipment,, ,,Stationary,, ,,Consumables,, ,,Transport,, ,,Lifting Equipment,, ,,Welding Equipment,, It will be also good if i could insert photographs of every particular item and copy of purchase recite.

I will need similar document for Personnel.

I will prefer freelancers who can provide samples of similar work with their bids.

If you know easy to learn software that can do all of this please advice!

Thank you!
Extra notes: