I started exercising/being active again

I been walking on my road after I get home from work and started riding my bicycle again. It rained yesterday so I didn't go out, but the burn in my legs is getting less with riding the bicycle. Also been doing squats to help.

Any tips for how I can go long distances on bicycle? I want to ride this bike trail to the end, but going back to the car is all uphill. So I'm looking for methods I can utilize for bicycle riding to where I can keep going long distances/long time.

Thanks.