Small frictions between lovers are inevitable. The important thing is that they will understand each other better in such frictions. Quarrels are not a problem. The problem is that they cannot communicate and understand each other well. So since you have realized your mistakes, you should apologize and explain well, so that you will understand each other better and your feelings will continue to deepen.
As for what gift to give, you can see what she likes.
DIY chocolate, make your apology, give it to her, full of romance and sincerity.
Couple rings, nothing can move lovers more than vows, engrave your own vows on the ring and give it to her.
There are many other small gifts, you can choose and have a look, it will definitely be helpful to you.