Near sighted, -1.00, 20/40 distance acuity. Is my vision still good enough so I won't need reading glasses?

For awhile. Near vision changes typically occur around age 40-45 and progress into our late 60's, called presbyopia. Nearsightedness does help the reading vision even into those early years, but because presbyopia progresses a -1.00 will eventually not be strong enough.
For now-yes. Myopia of -1.00 will allow you to read without correction most likely until your late 40's, or early 50's. The reading ability is a combination of your focusing ability, which you are losing a little of every year, and your nearsightedness. You will be reading menus for your friends for a while, but it will eventually catch up to you too-- just later.