So your current garden is a lawn that is bisected by a path? And you want to turn one half of the lawn area into a planting bed? If so, there are several ways you can do this.

1) The fast method: rent a sod cutter and remove the lawn. Amend soil as desired and plant.

2) The not so fast method: Lay cardboard or layers of newspaper over the area and wet down thoroughly. Layer on 4-6 inches of mulch or compost and/or soil. By fall this area will be ready to plant.

3) The hard work method: Instead of the sod cutter suggested in #1, cut the sod in strips and lift from soil manually. Stack the sod root side up in piles in an out of the way area to convert into compost in 6-12 months.

4) The chemical method: Use the herbicide of your choice to kill off the turf. You need to be very careful of overspray and drift, making sure no breeze blows the material onto other plants. After all the plant growth dies (may need more than one application), work the remains into the soil together with any other desired amendments.

i made a mistake describing it, the part i want to turn in to planting bed is not lawn, its just grass and lots of weeds. that part never had lawn just soil but over time grass grew there.
Thanks for the response.

With the additional description, I think you could just hoe the area, turn over the soil (or not...some people don't like to do this), add the appropriate amendments into the soil, and start planting.

This would be a bare beginning method but you can certainly get into more if you want to find out more ways to take care of and prepare the soil first.

You should find a hoe to be a useful gardening tool so you can go ahead and get it, knowing that it will get lots of use, even if you go with another method of preparation.

Good advice from gardenper. You could also ask around and learn which flowers "grow like weeds" in your area. The more of those that you find and like, the less soil preparation is a worry. It could be as simple as setting out plants and mulching around them.