If you’re training for a race that’s a 10k or longer you’ll need to work on two things: Distance and Speed. I think the problem most people have is they try to accomplish both at the same time, all the time. Meaning they think they should just increase their distance and speed a little bit each week. By increasing each week they figure they are getting closer to their goal. Unfortunately, you really don’t make much progress that way. It’s much more effective to work on distance and speed separately. Basically, for a few runs a week take an easy pace and work on distance. Then for one or two days a week run a shorter distance but push the speed. Either do intervals (alternate a couple minutes at race pace with a minute of slower pace recovery) or tempo runs (increase speed to about 80% of race pace for the entire short distance.) By focusing each run on one goal you’ll see better results sooner. And don’t forget the rest days because your muscles need time to recover.