Glad things were going well. I'm much more of a runner than a cyclist myself. One thing I hear is that the effects of training take about 2 weeks happen, meaning anything you do within 2 weeks of a race is of little benefit, and part of why folks often taper for a couple weeks before a big event. Overdoing things right off the bat seems to be a very common thing in runners, so just ease into it slowly. Don't worry at all about a 9:xx pace, heck half of my runs are 9+ even though I can do 5ks in 18 minute range. I tried to adhere to the 10% rule when I was starting over running, not exceeding my previous weekly mileage by more than 10% each week. And I rarely did 2 days in a row the first year, stuck with every other day for the extra recovery. Other advice I like to give is to keep your cadence up enough so your stride is short enough your landing roughly under the center of gravity and not sticking your leg way out and whacking your heels into the ground.