Thomm is right about the bike.
These days you can pick up older road bikes that roll well and have good gear on them quite cheap.
I paid only $60 for mine. Just keep in the lower gears and keep your cadence up to not load your knees up.

Regards,
Phill

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!