If you play electric guitar it’s very important to have an amplifier, in terms of practice, so i’d say get one as soon as you can
Ofc playing unplugged can be very good for practice too, but it all depends on the technique you’re practicing; i’ve used all kinds of methods to be able to identify problems in my technique. But honestly the most important thing, in my opinion, is to just analyze and try to get to the root of the problem, and then work from there and slowly build it up!
I actually picked up my guitar now, and i noticed that when i play a sweeping arpeggio i tend to leave my finger for a small moment on each string before lifting it completely, i think this helps to mute the string while i play the next note. When i play faster though, it’s unnoticable, but i think it might be a good idea to practice that so you don’t release the string too fast and create noise. Also make sure you don’t do a “pull off” and kind of drag the string downwards as you release it.