You need to search for ‘members only‘.

The next screen will show you a list of plugins that have been found – install members only (by Andrew Hamilton).

Once installed you can then activate and configure it.

Once configured – you may test to see if it works by logging out of your site and then trying to access it.  You will be resented with a login screen.  Just use your admin details to login.

Super.  That’s all very well – but you will not want to hand out your admin login details to all of your clients!  You will need to create a user account for each client or person that you want to allow access to your site.  you may do this through your dashboard > users > add new.  Make sure you give them the role of SUBSCRIBER.  Once you have set up a new user account – send the login details to that person.  When they wish to view your site – they will need to login first. They will NOT be able to access your dashboard at all – they will only be able to view your site.