For the bridal shower I would suggest that a bride doesn't plan her own but her mother, the groom's mother or the bride's friends can host the party. And I know etiquette says that mom shouldn't plan the shower but it's okay if she does. No one is going to think anything negative about it. Or your mom, his mom and your friends can all contribute different elements to a shower in your honor.
For the bachelorette party it's perfectly acceptable for a bride to plan it herself, but you have to decide if you're paying for the evening's activities or if you're going to have everyone split the bill. If you're planning the party, but don't want to foot the whole bill, make sure to tell your friends that you expect them to pay their own way so they don't assume that you're covering everything.