WPA security is weak while connecting to wifi

create a new named Network "Location" -- a collection of settings applied "all at once" when you select it. Every new named "Location" you create starts with all defaults, which lets you walk away from any errant settings that might be causing you trouble:

How to use network locations on your Mac - Apple Support

How to use network locations on your Mac - Apple Support

If possible (and it most likely is) set it to WPA2 and also set it to AES. With my router, both of the settings are in the same general area but are separate settings.

Also, even with the weak security warning it should still connect to the internet.

The lack of WPA3 isn't a problem. As you have found, the WPA2 AES setting removes the weak security warning -- but that isn't really a big deal and as Grant stated, you should still be able to connect to the internet whether or not you get the weak security warning.

In other words, you had 2 unrelated issues - 1) weak security warning and 2) not connecting to the internet.

The Router talks to each and every device using the SAME security protocol. once you set that for one, you need each computer and phone to make the same selection. Form what you have provided, that sounds like WPA2

once you have that set, what is the main symptom that remains?

status not connected? can't access web pages? self-assigned IP address?.

You have a valid local IP address. you are connected!

If you can't find a web site, that is a separable issue. here is what to try:

In the browser searchbar, enter 1.1.1.1 and press return.

if you get the CloudFlare** splash page, you have a Domain Name Server (DNS) issue, i.e., Internet phone number lookup is not working.

** CloudFlare is NOT part of the solution -- they just own the absolute simplest, easiest to remember IP address.

DNS problems can often be solved by deleting the numbers shown in:

system preference > Network > Wi-Fi > (advanced ) > DNS...

and using the (renew DHCP lease) button on the TCP/IP page.

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Also, best practice is to set IPv6 to 'Link-Local only" so that it does not interfere, but still provides Discovery of local resources.

Hold down the Option key while you click on the Wi-Fi Icon on the menuBar.

Choose Open Wi-Fi diagnostics, or the closest available. (do not choose the unless "create report" option).

allow it to run, and see if it can provide any additional tips.

what version of MacOS are you running?

system preferences > network > wi-Fi > (advanced) > Proxies ...

in the top box, uncheck any that are checked.

If there are none checked, you may have installed anti-virus software that has inserted a proxy, to be first to intervene in your network communications. This is completely un-necessary on a Mac, because it is not subject to random attack in this fashion.

Having ANY security at all should be YOUR choice. You should be able to choose NONE and still connect.

whose Router is this she we can shame them publicly?

why are you using a web proxy?

if this is from software NOT provided by you Employer or School, remove it.