I don't own a car and do all my fishing via public transport and Shanks's Pony.
I sometimes envy the car drivers and the amount of gear (****) it allows you to take and the freedom to explore more out of the way places, but having no car does mean you have to get creative.
First is the research to seek out stretches of rivers, canals or stillwaters within manageable walking distance of the nearest station and then the hardest part: cutting down the gear to the bear essentials. This is probably the hardest part and I still take too way much.
Here's my gear packed from a few weeks ago:
Rod bag with float & feeder rods (with reels attached) and landing net handle inside plus carp rod, landing net & mat strapped to outside. Then my rucksack carries seat, rod pod, scales, catapult, bite alarms, terminal tackle and bait. Oh yeah and a cheese sandwich and a kitkat