If you just want to know if you've gained fat and/or muscle, one method is using an impedance scale that measures body fat percentage.
They are incredibly inaccurate and you should not take their readings literally. Simply drinking water can have a big effect on the results. However, the readings are going to be fairly consistent if you take measurements at the same time every day (i.e. just as you wake up before eating or drinking anything).
If you track your weight and BF% on these scales, you can record them. Over time, you'll be able to see trend lines.
If your weight goes up and your average BF% goes up, then that means you're gaining fat at a faster rate than you're gaining muscle.
If your weight goes up and your average BF% stays the same, then that means you're gaining both muscle and fat at the same rate.
If your weight goes up and your BF% goes down, then that means you're gaining muscle at a faster rate than you're gaining fat. Or you've managed to hit that sweet spot of gaining muscle while losing fat.
If your weight goes down and your BF% goes up, then you're losing muscle.
If your weight goes down and BF% stays the same, then you're losing muscle and fat at the same rate.
If your weight goes down and your BF% goes down, then you're losing body fat at a faster rate than muscle.