For high-pass, something I like to do is I like to increase the frequency of the Highpass until it starts to noticeably affect the sound of the instrument, then dial it back a bit.
For equalization, you wanna aim to give distinct spaces for each of your instruments so the sound doesn't overlap too much and muddys it up too much, and Mud I would define as a rumbling sound in the mix. I didn't hear any in this one, but the EQ could be improved so everything blends a lot less.