Start charging for photos (shoot time is free, model pays for digital photos) and/or add a disclaimer to your model calls that you do not shoot nudes, implied nudes, boudoir, etc. and you should be able to filter out most of these people.
I do a lot of senior portraits, and it actually really helps when a parent and/or friend is there! I require a parent’s presence for minors anyway, but it’s always been an extra bonus that the parent is someone they’re familiar and comfortable with. I rely on mom/dad jokes to kind of break the ice, and then I encourage interaction with me/the camera, actual movement into a pose instead of a frozen pose, and I try to be as silly as possible to get some laughs.
Yes this is appropriate! Many if not all photographers do this starting out - it’s called trade work. Just let them know up front that you’re currently a hobbyist looking to learn and build your portfolio (it’s not too late, you can just shoot them a reply with like a date and time confirmation, thank you, and your “disclaimer”). Offer free unedited digital jpegs in exchange for their time (don’t offer actual raw files), and best case scenario is that they love the photos, post them on Instagram, and tag you. Worst case is that they don’t like them and just don’t share them - they’re not wasting any money. Either way, you’re gaining experience in a really fun way.
I’d echo what someone else said about getting a signed model release from each person you’re photographing, though, if you plan to actually use the photos in your portfolio or post them on social media. You can print off releases on paper and have them sign in person, or use Adobe fill and sign to send them via email.
You never need an excuse to make art and collaborate with people :)