Yes. This depends some on the dynamic the two of you have going. Some kids need more nurturing than others so try to recognise ques on time to change. Some are so interested in exploring when they begin walking that you find yourself chaseing them down to feed--time to transition. If baby seeks you out for feeds, enjoy it (for breast) but put water in bottles >1yr. They will toss it & accept a sippycup.
Yes. You have to wean the baby from either the breast or bottle. This should start at approximately 9 months of age by using either a sippy cup or a small liquor glass.