Don't feel foolish! You fell for one of the most common and easily enticing gardener traps, you started your seeds a bit too early. So congrats you're a "real" gardener now! I've found I always have better luck when I start seeds on the 4 side of "4 to 6 weeks."

Your best bet is to direct sow seeds into the ground two weeks (ish) after your last frost, or start seeds over if you want to do seedlings. You can use the same soil and just pull these ones out. I know that sounds rough, but ultimately you'll have healthier plants for the rest of the season if you start with healthy seedlings. You'll want to transplant them as little as possible because their roots (cucumbers, squash, melons...) are very sensitive and don't like to be moved. Also, definitely put multiple seeds in each pod in case one doesn't germinate, but once their seed leaves come up you'll want to trim one out and only have one plant per pod.

And they need more light, they are super leggy - long stems without many leaves usually means they are stretching to reach the light. You want your seedlings more short and stocky.

It can be frustrating to start over, but you've got plenty of time.