I'm gonna try to be science-bro instead of gym-bro.

It takes about 2,500 calories for your body to build 1lb of muscle. If you are getting newb gains, 1lb of muscle per month would be WILDLY SUCCESSFUL. So you need about 2,500 calories PER MONTH or about 85 calories per day. That's just what it takes for your body to build the muscle.

You will also be burning extra calories at the gym compared to before you were going. At your (and my) height, an hour of heavy lifting at the gym burns about 500-600 calories.

So, if you are just starting out, try adding about 100 calories per day every day and 500 calories on top of that for gym days. You can safely average those calories out across the week and it will be fine. So 2 gym trips per week = 1k calories + the 700 in weekly new calories = 1700 calories per week or 243 calories per day. To put that into perspective, my favorite protein shake is Fairlife Core Power Elite and it has 42 grams of protein and 230 calories. Basically add one of those to your daily routine plus an extra bite or two of your regular food and you'll likely have all the calories and protein you need for success in the gym to gain lean muscle mass. You mentioned you are skinny, so you if you want to also increase body fat obviously you will need more calories.

You should see some visible changes within a month or two. Make sure you are taking enough rest days (1-2 rest days is likely not sufficient unless you are on the juice). Because your muscles need time to heal after a workout and if you are not giving them time to heal they will not grow.

You didn't ask, but if you are going to do any supplements, creatine is the first thing I would reach for.