Well done fudgefeet! And DD.
I haven’t experience muscle pain in my legs. Achey knees with the occasional sharp knee pain for me. Is it a stretching thing? I need to get better at stretching as in I basically don’t do it. And I should, so I’m not the best person to advise.
In my extensive experience of having run 5k exactly four times, farontothemaddingcrowd, and only once outside of the c25k, I’m aiming to run 5k in under 30 mins. Then I think the next aim is to run 5k in under 30 minutes without feeling like I’m going to faint. After that, jury is out.