Is it better to just a rent a breast pump? I'm afraid to waste $ if I buy one and then I don't bf successfully.

If you want to breastfeeding fully, don't get a pump yet. Latch on first. If you do not wish to buy a pump, you can consider to rent first. Once your breastfeeding is stabilized, you can buy a proper pump. After birth, latch as much as you can in the hosp at nurses are there to help you