She hath no loyal knight and true, The Lady of Shalott. (line 62-63)
This is pretty much the closest we're going to get to talking about love in this poem. Love is one of the big things missing in the Lady of Shalott's life. Maybe we aren't even really talking about romantic love here. Maybe she's missing something more like a companion. Maybe the "loyal knight and true" would be a boyfriend, or maybe he'd be more like a protector and partner.
A red-cross knight for ever kneeled To a lady in his shield, (lines 78-79)
This is another version of the love or companionship that the lady can't have. This is a pretty old-fashioned idea of love, and it has everything to do with chivalry, and the way knights should behave toward ladies. It probably isn't much like our idea of boyfriend and girlfriend. Still, it's put in here to remind us of how little love the Lady has in her life. She and Lancelot cannot become the perfect knight and lady we see on Lancelot's shield.
From underneath his helmet flowed His coal-black curls as on he rode, (lines 103-104)
If all the stuff about knights and ladies isn't necessarily about romantic love, this definitely is. Come on, "coal-black curls?" These are like lines from a romance novel. Tennyson is letting us know that Lancelot is hot, and that's all we need to know about these lines.