Go here:
https://www.terasic.com.tw/cgi-bin/page/archive.pl?Language=English&CategoryNo=165&No=1081#contents
And look at the documentation that TerASIC provides for that board.
In particular, look at the RESOURCES tab, and at the DE10-Standard SystemBuilder tool you can download.
It is a standalone windows program that can help you configure the I/O definition for the board resources/pinout
that you can then edit/alter as necessary for your project definition.
It will build a .qpf, .qsf, .sdc, and .v template files for you to start with.
You also might look at some of the examples provided on the DE10-Standard CD-ROM image that is provided.
It is very useful, if you don't already have that software and files you should.