If you want to start taking great photos, look into prime lenses. They generally have lower F stop numbers which can allow for a narrow depth of field or more light/lower ISO photos. If you're taking pictures of people, I would only do a prime lens.
If you want budget lenses for Sony, you should buy a LAEA3 adapter. That will open up the door to older sony A mount lenses which you can buy used. I have the LAEA4 which has it's own focus prism which allows for fast sports autofocus. You can buy a used LAEA3 for a little over $100, and something like an old SAL 35mm f1.8 for $140 on ebay. This would be a great walkaround prime lens and will give you that creamy background blur you see in professional photos.