Courses
There's a four day science communication course coming up in Bristol. Registrations have closed but contact them and see if there's a waiting list. It's by the same team who run a longer MSc in Science Communication. This one runs 11-14 November 2024, £800 (some concessions available) https://www.jiscmail.ac.uk/cgi-bin/wa-jisc.exe?A2=PSCI-COM;afee3c77.2409 or direct link https://courses.uwe.ac.uk/Z51000095/science-communication-masterclass#entry
They also run an online course in Creative Science Communication and Public Engagement CPD Course https://courses.uwe.ac.uk/USSKNS15M/creative-science-communication-and-public-engagement, coming up in January.
The ABSW (Association of British Science Writers) has a list of some courses and modules here https://www.absw.org.uk/pages/courses-in-science-communications and yes I did just google 'science communication short courses' and lots of stuff popped up. I've not taken any of the courses myself so can't advise on them but I'd think any of them would be good https://www.google.com/search?q=science+communication+short+courses&udm=14
Public Engagement and Evaluation
Science Communication and Public Engagement are kind of two sides of the same coin - scicomm more about telling people about stuff, public engagement more about involving people in [subject / research / whatever]. Often the terms are used interchangeably but there is a difference.
This page from BIG the stem communicators network also has some other suggestions including the Methods for Change evaluation courses (I did one a few years ago, very good) https://www.big.uk.com/training - you can also find out about evaluating public engagement events from this document from QMUL colleagues https://www.qmul.ac.uk/publicengagement/support/evaluation-toolkit/
This is a free guidebook on Public Engagement - it is the result of a course run by the Alan Turing Institute on 'Public Engagement with Data Science and AI' but, apart from the specificity of the examples, the rest applies to any kind of public engagement https://alan-turing-institute.github.io/turing-commons/skills-tracks/ped/
Jobs
There are certainly a lot more people looking for science communication jobs so there's certainly a risk that you'll be up against people with specific qualifications (when I started back in 2003 it was a lot easier). However an awful lot of 'evidently science communication' jobs still aren't badged as such so I am always recommending that people browse through organisations' vacancies pages, hence my large list. My first charity scicomm job in 2003 was actually posted as a librarian / information specialist post.
All universities have comms and press teams to woohoo their own research for example, some are advertised through scicomm channels but plenty are categorised as comms or marketing.
Alzheimer's UK wants a £23k Communications Executive in their Science Communications team, based near Cambridge, closes in 5 days https://alzheimersresearchuk.current-vacancies.com/Jobs/Advert/3653948
Volunteering
I'd say pick a charity etc that you like and ask them. They may have a volunteering program in place and it might not include scicomm (...yet).
Very quick guide to scicomm ;)
I'd probably distill my 'how to scicomm' a bit like this, and I think it's probably fairly obvious but can be helpful to put it explicitly: it's not just about translating complex scientific information into plain English but also adding back context and knowledge ('background') that wouldn't need to be included for scientists.
People often say 'don't use jargon' and where you end up working may have a policy or house style on that, but I'd say 'use jargon but explain it', particularly in the health arena where people with a condition are going to be searching for info and will likely come across technical terms. One 'advantage' of jargon is that it flags itself up as a word someone doesn't know. Language to be particularly careful of includes the everyday words that scientists and doctors use to mean one thing and everyone else reads them differently. Classic example is of the patient greatly cheered by learning that their medical test has come back 'positive' which to them means 'good' but to their doctor means 'has a disease'.
Similarly protein (peptides vs eggs or chicken) or cell (thing with a nucleus, mobile phone, prison), or theory (hunch vs reasonably well-evidenced ideas) and so on.
Anyway, gosh I really need an editor don't I ;-)
Jo