Dfplayer mini sound module

What Arduino are you using? On most Arduino boards, pins 0 and 1 are the hardware serial and it makes no sense to use those pins for software serial.

Your improperly posted code is hard to read and follow with no formatting. And are the defines really in bold or did the forum software misinterpret your post because of the lack of code tags?

Read the forum guidelines to see how to properly post code and some good information on making a good post.
Use the IDE autoformat tool (ctrl-t or Tools, Auto format) before posting code in code tags.

You can go back and fix your original post by highlighting the code and clicking the </> in the menu bar.
code tags new

What does the code actually do that is different from what you want?

A schematic would help, too. Hand drawn, photographed and posted is fine. Include all pin names/numbers, components, their part numbers and/or values and power supplies.