Any body can pick up a mower and cut grass...not everybody is professional about mowing practices though...but all that takes time anyways. I started with an old 22"crapsman I found on the side of the road for free, used my battery operated yardworks trimmer, and a broom all in the trunk of my neon. I would have to take the 2nd battery & charger with me and plug into my clients outlets at the side of the house. Start small & use what you got if it still works. Only buy equipment if you absolutely NEED it. If you really do need a bunch of new equipment, buy new handhelds and a used mower with low hrs...you have to ask yourself if you really need it.
Spend as little as possible and buy stuff as you need it. You definitly don't need 40k to start. You don't even need 5k!