I will be flying Copa from Panama City to San Jose in Costa Rica Economy class as a United Star Alliance Gold.

There seem to be few Star Alliance benefits - no free seat selection, no free bag. Is there some way to access these benefits ? I assume I have access to the lounge but I understand it is subpar.

Thank you.

You do get extra baggage allowance, you do get priority checkin, priority security access, priority boarding, and you will have lounge access. The Copa Club in terminal 2 is gorgeous but the food is terrible. The Copa Club in terminal 1 has terrible food but it's a least a little bit quiet.

You should have free seat selection if you correctly input your UA MileagePlus number into the reservation. If you can't do it online give the Miami call center a call and they'll do it for you... unless you got basic economy. You don't get the extra legroom seats for free in advance. If they have them available at checkin and you ask very nicely and point out you are *G, sometimes the agent will do it for free, but don't count on it.

Do I get free baggage as a star alliance gold menber when purchasing economic basic ?

Yes, you will get one 23 kg baggage free

I believe it's only me. Sometimes on UA, it also applies to my accompanying passenger in the same PNR

I see on the Copa site that *G (United 1k) gets free seat selection. If I may piggyback the OP’s question, does the benefit extend to companions on the same PNR?

Edit: I called the Miami Copa office and they denied that my wife’s *G (1k) status includes free seat selection, even for her. We’re booked in Economy Classic with a T fare. I’m surprised that this would be the case…

Getting two baggage allowance whilst booking Guayquil-PTY-MIA on Economy Basic, but no free seat selection

On a Max, do they let Star Gold select economy extra seats at check in?

The first answer is No. However, at the airport, they do honor Star alliance gold at the check-in counter and a lot of times get you economy extra without fee.
This is more secure if you are a + Premier Gold (united). Well I speak from my experience, I have a cousin that was 1k in United. He just comment his star alliance gold status to the lady, and a lot of times got economy extra for free.