It's a good idea to buy only what you need to save money. The less money you spend on operations the better because you will always want more money to grow your business and pay yourself a bigger salary. Here is a list of lawn care equipment that is most necessary if you're operating on a very tight budget.

Vehicle: Yes, it's okay to drive a used vehicle for your new business!
Trailer: A good rule of thumb is to figure out what size trailer you need and buy the next size up because you will need a bigger mower and additional equipment in the future.
Commercial Lawn Mower: Research what size mower you need and buy the next size up.
String Trimmer or Line Edger: Also referred to as a weed wacker, strimmer, and grass trimmer. These items are extremely easy to operate and manuver.
Portable Gasoline Container: Something small to carry extra fuel.
Handheld Power Blower: Used to blow grass, dirt, and leaf away.
Safety Equipment: Ear Plugs, Gloves, First Aid Kit, and safety cones

Note: All the equipment purchased can be very expensive if you buy new locally. The best way to get new equipment at better prices is to buy from an online store. After purchasing the equipment, be sure to label every tool with your business name on it to avoid future confusion about ownership that can easily happen while on the job.