i want to do some updates to kitchen and bathroom, but im renting so i cant make any major changes.

Target, is a great place to get good design for your kitchen. Home goods is also inexpensive. All you really can do when renting is accessorize and keep out the clutter.

Ditto the first comment and if the rooms are functioning well enough, look at the lighting. Sometimes changing bulbs (edison to halogen) will add some depth and drama. Open a can of paint if that's OK with the owner. Use a deeper (not darker) color to set off the existing fixtures. Most of the time a land lord will paint everything off-white and that can make things look worn or just boring. Another trick is to paint the ceiling a pale blue with grey tones. It looks with in daytime and reflects the artificial lighting at night which sharpens the view.
After that head to one of the big box retailers for some accents. One strong piece of art on a wall will add oomph! Finally, edit well. In other words use a strict hand when finishing the rooms. Less is more and don't be afraid to take a risk with your accessory items.

Try changing the outlet plates and switches with stainless steel ones makes things look a bit cleaner and inexpensive. If there are a few knobs you could replace, try that too :)

Fabric applied to an accent wall can always brighten a room - use liquid starch, then you can just pull it off and wash the wall when you move, no repainting needed. You can get some really great patterns on sheets whatever your taste runs to be it modern or traditional. I love the look of traditonal rugs in a kitchen too especially if the floor covering is less than desirable - you can get them in indoor-outdoor styles that hose off when dirty. Same goes for bathrooms which unfortunately usually have less room for chg. Coordinating towels, shower curtains and bathroom necessities helps too so you don't notice the pale white tile walls as much.