Strongly agree with and endorse this advice. Learn to communicate.
To OP: If you think learning a programming language will make you a better English communicator you're on the way wrong track.
If anyone is using jargon, I recommend that as a team you make it a point to avoid it. No one should be required to well-versed in anyone else's jargon to collaborate on a job and it indicates they have some communication shortcomings as well. Work on it together.
Tech collaboration can be maze-like at first because I really think programmers are usually terrible at talking about our work to non-programmers. Avoid learning Java as a means to understanding someone else's English.
Yes, if you can get them to stop using jargon at all, that would be ideal. Jargon is, by definition, meant for communication within a discipline, and inappropriate for interdisciplinary conversation.
That said, translating jargon to English is a skill, and I wouldn't expect these developers to be able to just flip a switch and turn off the jargon. OP is going to need to gradually transition them to better explanations. A good way to do that is to constantly ask for definitions to terms you're unfamiliar with, and use the non-jargon versions yourself.
To OP: If you think learning a programming language will make you a better English communicator you're on the way wrong track.
If anyone is using jargon, I recommend that as a team you make it a point to avoid it. No one should be required to well-versed in anyone else's jargon to collaborate on a job and it indicates they have some communication shortcomings as well. Work on it together.
Tech collaboration can be maze-like at first because I really think programmers are usually terrible at talking about our work to non-programmers. Avoid learning Java as a means to understanding someone else's English.