Feeling a presence is just that, a presence. It doesn't mean much. I wouldn't count it as harmful just yet. Just give a heads up, a demon looks like what you'd think a demon looks like. They also feel like what a demon would feel like, if you're perceptive enough. To be frank, it could be anything at that point. Most people aren't great at summoning demons unless it's their first time doing any magical ritual and everyone seems to benefit from beginner's luck.
Past that, give it a few days. If you've done a banishing or prayed for protection, then the effect should leave you. After that, you'd have to just study and practice occultism a lot to figure out what happened with it. That usually takes several years anyway.
As for the girl, everyone's entitled to their beliefs and opinions. Even if they are wrong, crude, sexists, etc. While it may be upsetting now, the reality is that each person does need to learn humility and respect but often, it comes with age. The older, usually the wider but that grading is on a curve so... there's that...
Anyway, there's also someone newbies have to learn as well. That there are greater forces and magicians moving within the cosmos, on Earth (both the physical plane and elsewhere) and in the streams of the Heavens. There's been shifts of currents over the years and as horrid as it may be to the senses, there's good reason for it. Sorry but that's just the way it is for actions to push against other actions. I'd encourage you not to be so adversarial to someone who is ignorant or malicious. We all get humbled later on. Trust me. Best of luck!