Add an image widget to your side bar (or footer if you prefer).

I use the image widget that comes packaged with Jetpack (don't panic, I only use a few of the Jetpack bells and whistles) but any other image widget that includes an external link facility will do.

Add the link URL (for when the image is clicked) to link directly to your social media account eg https://twitter.com/myusername

Make sure you tick the box that opens the link in a new window/tab (you want the visitor to return to your site)

Save and close.

You could probably do this using the native Text Widget, rather than an Image Widget if you know how to code and don't want to add an image plug-in.

I can only get as far as adding the image and an alt title, using a text widget - not the clickable link.

eg <img src="add your image url here" alt="Twitter followers" />

Any help gratefully received and I will update the training (crediting you of course).

UPDATE: found this link which shows how to connect an image with a url in a text widget

https://en.support.wordpress.com/links/text-widget...

One less plugin to install!