One thing I found super helpful is checking if your WiFi adapter supports “hosted network” or the newer “Wi-Fi Direct” features-some older/cheaper ones just don’t. If the Mobile Hotspot option is grayed out, updating your network drivers from the manufacturer’s site sometimes sorts it out. And, yeah, Windows usually only lets you share Ethernet or cellular internet over WiFi, not share WiFi over WiFi with the same adapter, unless you have a second USB WiFi dongle (super handy and cheap on Amazon!).
Also, for security: always use a strong password for your hotspot, and remember that sharing your connection opens up your network-be careful what you share and who connects! For third-party tools, Connectify Hotspot is popular, though it’s not free. If you still have hotspot trouble, sometimes just running the built-in Windows troubleshooter (Settings > Update & Security > Troubleshoot) actually helps!
Would love to know if you get it working, or if you try Connectify or picking up a second USB WiFi adapter-totally opens up hotspot options!