I’m also relatively new but I’ve made wines and ciders and beers off all batches from 750ml to 5 gals. It looks like you started that batch without enough head space. The yeast multiplies and gets like how it is in the picture, if you don’t put a blow off tube (basically an airlock but instead you put a tube where the airlock would be, and the other end in cup or jar of sanitizer or vodka or anything clean) This will allow the yeast to rise. Otherwise you’ll get yeast in the airlock, which will block co2 from escaping, and the vessel will pressurize.
Fix: Blow off tube (tube diameter: size of the 1gal mouth or size of the airlock hole)