How do I get my yard ready for planting flowers and plants?

OK I am new at all this and I already killed some poor innocent tulips, so please stop the madness.I dont know if I what I need to use to plant hostas, like fertilizer manure soil compost. Do I use one or two or all and if I am planting flowers and plants in the same area do I need to use one thing in one area and a dif thing in the other area, AHHHHHH I am a messs but I want flowers!!!!