Running this year and goals

I want to run a marathon in April my fastest 5K is just 27 minutes and some change fastest 10 k is 1 Hour and 7 minutes none of my runs are over 10 miles I am 5’11 and about 220 my goal for sub 5 hours and to run it 25lbs less when I started this journey I was about 275

I want to run a marathon in April my fastest 5K is just 27 minutes and some change fastest 10 k is 1 Hour and 7 minutes none of my runs are over 10 miles I am 5’11 and about 220 my goal for sub 5 hours and to run it 25lbs less when I started this journey I was about 275