Amend website to add a member log-in system

I run a golf society that has a html based website, www.bartongolfsociety.com. I do all the admin for the site including booking all the golf events, keeping records of payments etc. I was diagnosed with cancer last year and although I've had surgery and been given the all-clear, I really need to lighten the workload on this (I have been doing it since 1994). At the moment all membership information, payments received, balances etc are stored in an access database and I email all the members via a package called GroupMail, so I can mailmerge fields etc. I'm really looking to move the database to a 'cloud' based system so that other people can become administrators and keep some of the records for me. Ideally then I'd want our society members to be able to log-in and view their balances etc (with some fields viewable to admins only). I don't necessarily need a function where they can sign-up for events online, but it could be a worthwhile addition if not too complex. I don't need the whole site re-designing, just to have the functions mentioned above. I can send a sample of the data to show the fields needed if desired.