Begginer wanting some advice

Hi new to forums, and basically just wanted some pointers or tips specific to me.

First off i'll describe my circumstances, i'm a 23 yo male and have just started taking steps to stop smoking. I am currently running 5k in 26.31, the route i (and a couple of running buddies) take varies in terrain i.e sand,grass,gravel,slopes,steps and pavements. We do this 3-4 times a week mixed with weights on leg rest days, also run with running club on a monday (just started). Would just like some advice on how to better my time,am i doing it right, what i need to improve etc. 

Anything would be gratful.

Thanks in advance.

John