First run for the season

Just completed my first run for the season. I haven't really done much running in the last 10 years so thought I'd commit to it a bit more this summer. London is a great place to run as it's flat and the parks are huge. Just running around my local park (Clapham Common) is 6km. I managed to complete it in 32 minutes which is the same time I did last September so I'm pretty happy with that.
I have a free app on my phone called SportyPal which has a friendly female robot voice tells me the time at every kilometre. It also creates a map on google to show where you went and gives a graph of your speed. Not bad considering it's free. My new ear plugs held up well too. Didn't have to adjust them once.
I was wearing a hear rate monitor too and mostly sat around 161 bpm. It seems that is my sweet spot. Hopefully with a bit of interval training I can increase this.
My aim by the end of summer is to run 6km in 27 minutes which is a 4.5 minute km.
Below is the route I took (slightly altered to omit my start/end point).