Why don't some member profiles (including mine) offer the options of "Follow" and "Message" below the large avatar on the member page?

Jacobsonbob,
Go to the upper right hand corner on the AgingCare home page. There you will see a broad band that goes from blue to green. Your "avatar" is up there in a circle. Either a picture you put up or your first initial. Press on that. You will see a list appear below it. Press on "settings". Now a line will pop up that, below the main topics will have "privacy" . Press on that and all the privacy options will show up one at a time. You will press yes or no to sending and receiving messages.
I often turn mine off when I get yelled at too much. Then turn it back on when I am ready.
Good luck. It takes a while to negotiate all options and I have found out we can check on other posts going back some time. I still haven't figured out how to do that one!
Also be aware that when you send someone a message you can mark it private if you don't want everyone on site to see it.

Thanks, everyone, for your help! You're a great group of people (which, of course, I've known for a long time!).

Bob, let's just try this: 

On your personal page, click on "Settings" on the toolbar below the main Aging Care toolbar, then click on "Privacy" below that.

This is what that page contains:

"Share Activity
Allow other members to see the activity on your profile page.
The following will be shown on your profile page:

Answers you have provided
Helpful votes you have received
Likes you have received
Members you are following
Members who are following you
Remember: Things you hide from your public profile will still appear in your view.

Show Location
Allow members to know the city and state that you live in.

Show Public Messages
Allow other members to view public messages that have been sent to you.

Allow Messages
Allow other members to send you public or private messages."

If "Allow Messages" is set to off, you won't get messages, and I assume not be able to send them.   Just click on the circle and you should be all set to get and send messages.

Let us know if this works.

Bob, let's try this.  I just sent you a private message.   Click on your name and you'll be taken to your private page:  https://www.agingcare.com/members/jacobsonbob.

Do you see the message?  If so, click on my screen name and you'll be taken to my private page.    You should see a "Messages" section, with a large "Messages" , and a pale sea green box stating "Messages", a small box stating "Private Message", and white background section for the messages.

Try that; if it doesn't work and you can't get a message to be sent, post again, and either I or someone can help you change your personal settings.

As GardenArtist noted, it is up to individual users to decide if they will allow others users to contact them through messaging. In the Settings Tab, under the Privacy settings members can turn on/off the view of their activity, location and messages as well as the ability for other members to message them directly.

"jacobsonbob,"

I'm messaging you now -

Bob, I also could leave a message, and follow you.   I've noticed though that a lot of the one time members don't enable those functions, which they have to do through the settings sections in their profiles.  

I think some of the newbies aren't really aware of this, and/or others just don't want to be privately contacted.

Bob, when I go to your profile I have the ability to leave you a message. ?