"I also believe" sounds better, but "I do also believe..." can be used for emphasis, but the latter is much better in my opinion.

"I believe..." or "I also believe..." is a normal way to express opinions. When you say "I do also believe..." the stress is on "do": I DO also believe. This means you are stressing that you really do believe what you have said. This is different than a simple statement of what you believe ("I believe..."). So use "I believe" or "I also believe..." for expressing opinions.

The first one is better, and you can also say " i do believe too"

lol same things i was thinking about days ago :)