How do I merge 2 Vendors together that were entered twice?

Nice to have you in the Community, @info112. I can assist with merging vendors. 

You can do this process in QuickBooks Online with the following steps:

1. Click Expenses on the left navigation panel and choose Vendors.
2. Select the name of the vendor that you don't wish to use and choose Edit.
3. Change the Title, First name, Middle name, Last name, and Suffix to match that of the vendor that you're merging it with. Also, you will want to ensure that the Display Name is also the same.
4. Click Save and confirm Yes that you want to merge the vendors.

I've included a brief video to serve as an example of this:

Please know that this process cannot be reversed once performed. For additional information on this, such as how information is retained, I recommend the following article: How to Merge Accounts, Customers, and Vendors.

That's it. I'm sure that you'll have the vendors merged in no time.

As always, I'd be glad to answer any other questions that you have about this process or anything else. Cheering you to a pleasant and productive weekend ahead.