Magento 2.3.4 Need to add new fields in member/ client shopping form ( backend frondend). Also Web server is configured to run Magento from %MAGENTO_ROOT% directory. Need to be changed. Admin panel discovered at a common URL, need to be changed

Magento 2.3.4 Need to add new fields in member/ client shopping form ( backend frondend). Also Web server is configured to run Magento from %MAGENTO_ROOT% directory. Need to be changed in %MAGENTO_ROOT%/pub as a Web server root directory. Admin panel discovered at a common URL. Need to be changed in custom url. About additional fields: Is good to open the additional fileds by ajax. if the client is Company / Business need to fill his company bussiness info. Additional fields need to be. Business Name: Business Address: Business Area/ Town: Business Prefecture: Business Zip Code: Business Tax Registration Number: Business Tax Department: Business activity: Comments: (field) Obligatory fields will be all excpect the comments field. The above fileds need to be presented frontend - backend and in order's email: The text will be in Greek Language so need to know where we could replace these texts from English to Greek Need to fix first in back up site and then to main site Full instructions how can we fix them to main site