Thanks, John. I was quite fortunate in that in my first few days I found an article written by Kelly Eden offering support to new writers and contacted her and she agreed to assist me. You could try her and see if she has some time.
If not I would reach out to the writer of an article you’ve liked and ask them. I think it never hurts to ask and I’ve found most writers in Medium to be quite supportive.
Failing that there are some Facebook Medium groups. People on those groups are helpful and if you perhaps introduce yourself and ask if anyone could assist in looking at one of your drafts you should get some volunteers.
Let me know how you go- Medium can be a tough nut to crack but if you can find a mentor it will make the journey a lot easier.