My suggestion is to find out whether she has a boyfriend before you confess your love to her. Otherwise, if you confess your love to her rashly, both of you will be embarrassed if she has a boyfriend.
If everything is fine, you can buy a bouquet of roses, choose the number yourself, and then choose a gift carefully prepared for her, such as a necklace customized with her name, an agate bracelet engraved with her name, these gifts are specially made for her, and she will definitely be very touched. When the time comes, you can put the necklace or bracelet in the roses and say to her: Be my girlfriend, I will love you forever.
You can also pay close attention to what she likes, and then buy her something she likes as a gift. This can also show that you often pay attention to her and that you know her very well. Generally, girls will be very touched. If you don't know her very well, give her something that girls are more interested in, such as plush toys. Choose something with better texture and prettier. Generally, girls will like it very much.