Can I visit the Mekong delta and Halong Bay without booking a tour? I have read mixed reviews.
For example, I read that you can do Mekong Delta on your own. However, I've read not to try & visit Halong Bay by yourself bc it takes to long to get to from Hanoi and the cost of a tour compared to doing it yourself is about the same. I heard that a tour is over $100. I need help, thanks!

If you go to Cat ba island you can get a full day tour of Ha long and Lan ha bays for 20 dollars, including lunch, kayaking, swimming, floating fishing village, and a stop off at monkey island for a climb to the 360° viewpoint.

The Mekong Delta is easy to do by yourself. However, getting there by public bus from HCMC can be a bit of a hassle. I booked a 1 day Mekong Delta tour with Sinh Tours (a bit under $20). I did all the tourist stuff including lunch then got the bus to drop me at the bridge in My Tho so that I could spend the next 3 weeks just wandering around the Delta by myself. Public transport was pretty easy to find and there were lots of accommodation options.

The Mekong Delta is easy to do by yourself. However, getting there by public bus from HCMC can be a bit of a hassle. I booked a 1 day Mekong Delta tour with Sinh Tours (a bit under $20). I did all the tourist stuff including lunch then got the bus to drop me at the bridge in My Tho so that I could spend the next 3 weeks just wandering around the Delta by myself. Public transport was pretty easy to find and there were lots of accommodation options.
You can visit Mekong Delta and Halong Bay by your own quite easy. From HCMC, you can catch a bus to Mekong Delta and enjoy a night in there and join floating market in the early morning. For Halong Bay, you can catch the shuttle in Old Quarter or bus at My Dinh station to get Halong. However, if you want to travel by cruise in Halong bay, you should book cruise in Hanoi