Is my MacBook actually charging?

click the battery icon in the menu bar. it says Power Source: Power Adapter, and under that either charging, not charging, or charging on hold. 'on hold' is usually optimised battery charging, macOS holds it around 80% if it thinks you'll be plugged in for a while. that's normal and why the number sits still. you can tap Charge to Full Now in that same menu if you need it full. if you want the real numbers, hold Option and open the Apple menu > System Information > Power. it shows whether it's charging and the wattage the charger is giving. a low wattage there usually means a weak cable or a phone charger.