The lyrics of "I Want To Hold Your Hand" are, to be fair, little more than cute. There is practically no substance to them at all. Fully one-third of all the lines in the song are "I want to hold your hand" (we counted).
But cute doesn't mean bad. Fans obviously liked the lyrics well enough, considering that the song was #1 for seven weeks.
The words have what we professionals call the "awww factor." These Hallmark card lyrics are great for such things as, oh, I don't know, a video of otters holding hands. Part of this "awww factor" is in the delivery. The pauses in the delivery of each verse convey a kind of stuttering, bashful feeling. At the same time, these puppy-love singers are bursting with the need to confess their love. So at the same time that John and Paul can't get a line out in one piece, singing "Oh yeah, I'll… [pause] tell you something," they confess (in glorious vocal harmonies nonetheless) "I wanna hold your hand" and "I can't hide."
The actual content of the lyrics revolves around feeling versus speaking. That contradiction in stuttering delivery and harmonious confession is perhaps caused by the hesitation, yet feeling of absolute need, to say what they mean. The oft-repeated lyric "I wanna hold your hand" is a mushy kind of resolution of this.