Don't worry about the serve. The serve is the most difficult skill in tennis and should be last.
There are almost no novices who can serve well in one month, but there are novices who can simply pull in one month.
Therefore, it is not fair to simply measure the difficulty of tennis by the difficulty of serving, because the difficulty of serving in badminton and tennis is not the same.
In front of the answer are very good, in fact, summed up a problem, hair force habit. The dynamic habits of tennis are not what you might expect.
The novice is not good at body power, lack of pedal turn, no turn, all rely on the arm to play, the quality of the ball is naturally very poor.
Plus, beginners usually think the ball is heavy so I have to swing it hard, so it's probably going to fly. In fact, your arms should be relaxed.
So what you need to get started with is the right power habit, and with that you're halfway there. This is more important than anything else. A lot of old tennis players don't really get the hang of it, because they're all wrong. You've only been here a month.