Hello @NH_20,
Welcome to the QIIME2 Community! :qiime2:
Here is a tutorial to import pre-merged data. I hope this helps you import your data.
Here and here are discussions for how to do quality control with pre-merged reads. If you are unsure how to run quality control commands discussed in those links, I would recommend this section of the moving pictures tutorial.
I hope this helps!
Chloe 