Anyone know how to connect MacBook Pro to personal hotspot when self assigned IP says it cannot connect to internet?

You mention a self assigned IP. Does this mean you have a static IP address set on your MacBook? If so it won’t work. You need to make sure that in the network settings and under the advanced button that your TCP/IP is set for “Using DHCP” and under the DNS setting that you don’t have your Mac set to use a specific DNS IP address. If you don’t have your Mac set to automatically configure those settings to whatever your Hostspot uses it won’t connect properly.

Set up your personal hotspot device correctly. For example if your hotspot device is a phone make sure it is configured to act as a hotspot. It will connect to the Internet then issue a local private ip address to your computer. This similar to how a router does the same thing. So if your hotspot is issueing an ip address to your computer then the problem lies with the hotspot device not being connected to the Internet. Make sure your computer is not also connected to another network gateway at the same time.

Every Internet-capable device create a self-assigned (not Routable) IP address for itself when it starts up. They are pseudo random in the rage 169.254.xxx.yyy. It then uses that address to broadcast a request for a Router to send it a better local IP Address using DHCP. It needs the self assigned IP address to identify itself uniquely to the Router.

This happens so quickly on a properly-working network that most Users have never seen a self-assigned IP address.

But when the self-assigned IP address persists, and is not replaced by a local IP Address in the same range as the Router, then there are fundamental reasons you and the Router are not communicating properly, like broken wires or too far away to hear each other. (Or in this case, Phone not quite set up as a HotSpot yet.)