How to get Ethereum from my early 2016 Ethereum Wallet

In Feb 2016 I mined less than 1 Ethereum (says 0.70 probably closer to 0.69). I can see the funds on Ethereum-Wallet-win64-0-3-9, which is also from Feb 2016. I just ignored this for years as I didn't need the money but I do now.

I tried to send a very small amount to a Coinbase account I made. Coinbase gives me the same address for receiving ETH from either "Ethereum" or "Base" Networks, so that's the address I used. I tried a small amount to test (0.001) and it's at 0 of 12 confirmations for several hours now – so it did not work. The first gas fees I tried were too low, but it did accept a higher gas fee and I had to input my password so means it's talking to the network to some extent right?

Under my 2016 Ethereum Wallet application, there is a "Wallet Contracts" section and an option to "Add Wallet Contract" and I don't have anything there. But I'm wary to try to do much more with this nearly 9 years old Application. When I click "Etherbase" with the key symbol it says "Accounts can't display incoming transactions, but hold and send ether." So I should be able to send from here, right?

I downloaded Ethereum Wallet and Mist Beta 0.11.1 – windows hotfix from Github today. But it doesn't work on my PC. "Checksum mismatch in downloaded node!" with an MD5 listed and then "Please install the Geth node version 1.8.23 manually". Maybe because I have an older version?

How can I get this Ethereum to my Coinbase account?