I was in a similar position to you when I entered a half marathon having not run any long distance since I left school 33 years ago. I started off doing a short distance of about a mile which was a run/walk/run. this eventually was a full run then I increased the distance 2.5miles, 4 miles, 6 miles & then the maximum run I did in training was 8 miles. I used to go out at least 2 times a week sometimes 3 depending on how I felt. I started in Feb & I ran the half at the end of May in 2hrs 20mins but I’m old & slow.
Most training schedules suggest a run day followed by a rest day – I used this one as a rough guide. I found it difficult to fit in genuine rest days for recovery as I play football on Wednesday, I do a 28mile ride to work & back most weeks & I ride at the weekends.
My advice would be to get your feet checked out by a proper sports shop not JJB or sports world so you get the right running shoes for your feet. I had mine checked out & I never had any problems with my shoes/feet. Build up the distance slowly don’t try to run too far too soon. Run at a pace that you can sustain the longest I found that running & still being able to hold a conversation was the right pace for me. Maybe join a local running club to go running & get the benefit of their experience.
Good luck & enjoy the day.