I Gave My Younger Brother the Wrong Advice About His Crush

So here's my story. I have this younger brother who is kind of an awkward kid when it comes to social stuff, especially with girls. He’s really into a girl at school named Jenna, but he has no idea how to go about getting her attention in a way that feels natural to him. This girl is sweet and nice enough, just really quiet and not much of a talker unless she knows you well, which means my brother doesn’t stand much of a chance with the usual tactics like asking someone out or sending them love letters (which he's tried, but Jenna barely even responds). He asked me for advice because I've always been more socially adept than him. I told him to be himself and try doing something that could show her his interests, maybe bring her one of those giant stuffed animals he collects just so she can see what they look like up close or something along those lines, thinking it might help break the ice and give them something to talk about if they end up running into each other. He did this a few days later and brought one of his prized possessions, a big pink unicorn, straight over to Jenna’s house after school with no invitation or prior warning whatsoever. She was out at the time, and when she returned, he left it on her doorstep and ran home crying, completely embarrassed that his plan went so terribly wrong. This wasn’t exactly what I had in mind when suggesting something sweet like a gift but it's my fault for not being clearer about my intentions. Ever since then, every time we talk about Jenna or dating in general, he looks at me as though I’m the worst big brother ever and that nothing will ever work out with her. And while part of me feels bad for giving such poor advice, another part is annoyed because really, it wasn’t my responsibility to make his teenage crush dreams come true.