Mac mini m1 Can I hook monitor with usb and sound bar with HDMI at the same time

Yes, you connect one monitor via a Thunderbolt/USB port and another (?) monitor w/sound bar via the HDMI port.

Mac mini (M1, 2020) - Technical specifications

❝Video Support

• Simultaneously supports up to two displays:
• One display with up to 6K resolution at 60Hz connected via Thunderbolt and one display with up to 4K resolution at 60Hz connected via HDMI

• Thunderbolt 3 digital video output supports
• Native DisplayPort output over USB‑C
• Thunderbolt 2, DVI, and VGA output supported using adapters (sold separately)

• HDMI display video output
• Support for one display with up to 4K resolution at 60Hz
• DVI output using HDMI to DVI Adapter (sold separately)

Audio

• Built-in speaker
• 3.5 mm headphone jack
• HDMI port supports multichannel audio output❞