add functionality in core php theme php expert required

i have install a theme from codecanyon want some modifications Requirements 5. Tab to search by User or equipment. When selecting a user, a screen should display showing details of this user and all currently assigned equipment. From here I should be able to select any equipment (Multiple, MAX 6) and click on change ownership. Should then take me to a screen to search all active users and pass ownership of those equipment I selected. From this transaction registry should be created for each equipment that changed ownership. Also this should create a PDF with all the details of the transaction. PDF should have a non-repeatable correlative number. PDF number format: Prefix: 0101-Year-Correlative. Example: 0101-2020-00001, 0101-2020-00002 Transaction History: a. ID (KEY) b. PDF document c. Employee making the ownership change (LOGIN) d. Old Owner (USER ID) e. New Owner (USER ID) f. Equipment (EQUIPMENT ID) g. Date h. Description *From history transaction I should be able to re-generate the PDF using all transactions that have the same PDF number. c, e, f, g are obligatory fields. theme [login to view URL] do read the requirement first then bid on this project write "i can" in start of proposal if you read the requirement