Access Database Support for small U.K. Charity

Our technical support volunteer (who originally designed the database) recently passed away. We need a replacement to support one database operative and two database readers who regularly download the latest updated data files from a remote online MS OneDrive server. We operate a simple ‘split’ database with one front end application mdb file, which rarely changes, and one data mdb file which, as stated, is regularly updated by the data input operative.
All data input is done on one single PC . There is no networking or remote data input. Everything is working fine at present but it is essential that we have a replacement Access expert to advise and resolve issues in the future.