Arriving in July and should be checked in at our hotel (Hotel Electra Metropolis) by early afternoon.
Taking a guided tour that includes Cape Sounion, Poseiden's Temple, Acropolis & Museum the following day.

Suggestions for activity/sites to see on our first evening in Athens?

Looks like we're near the National Gardens.

Relax, take a casual stroll through the Plaka, do a little shopping, find a restaurant for dinner al fresco, enjoy the evening buzz in the air.

Take an evening stroll up Apostolou Pavlou if you can. It's a beautiful walk up a pedestrian-only street with views of the Ancient Agora and Acropolis. It's a place of tranquility in the middle of the city. There are outdoor cafes with a view where you can stop for a cappuccino freddo or a drink. The nearest metro station is Thissio.
https://www.athenskey.com/apostolou-pavlou-street.html

Enjoy the walk around night lit ancient sites. All archaeological sites are beautifully lit up at night. Tower of the WInds, Roman Agora, Hadrian's library, etc. Look up and see the night lit Acropolis from various angles. Walk up to Anafiotika for dinner.

Watch a unique theatrical performance of Ancient Drama... Its an experience you do not easily find... Fimonoitheater.com
Or
Have an open air movie night

If you aren't too pooped, have dinner in Lycabettus Hill: https://whyathens.com/lycabettus-hill/

DH and I were there many many moons ago and it was very pretty. According to the link above, it is easier to get to now.

>>> If you aren't too pooped, have dinner in Lycabettus Hill.
A major emphasis on aren't too pooped. There is a funicular up the hill, BUT, the station is practically half way up the hill. This means unless you are taking a ride up to the bottom station, you walk A LOT just to get to the funicular station.

Good to point out, greg. We took a cab to a resto when we were there in the way back when!

You might check to see if you can catch a performance of folk dances at the Dora Strata Theater.

If it is Thursday watch a theatrical performance of Ancient Drama. Athinais theater Oedipus Rex... Perfect

​​​​​​Www.fimonoitheater.com

Whats the best place to eat, I need to get the plug for Athens !