Fishing was very important to early Stone Age people, and fishing is probably what brought the first people to Greece. No part of Greece is more than about forty miles from the sea: a couple of days walking. So Greece was a great place to fish and to collect seafood like mussels, octopus, oysters, and shrimp.
A good source of obsidian
Greece has a lot of good ports and beaches. Plus there are a lot of small islands as well. Some of these islands are a good place to get obsidian, which might be another reason why people moved to Greece.
Not great for farming
On the other hand, the soil in Greece is not very good for growing things. There are a lot of mountains that make it hard to walk from one place to another, and there is never enough fresh water. In Greece, plants tend to be small and scrubby: thyme bushes, sage, olive and fig trees, laurel, and little thin evergreens like juniper and oleander.
Traders, sailors, pirates, raiders
The combination of good sailing and lousy farming encouraged Greek people to get their living from the sea. Many Greeks were fishermen. Other Greek people sailed trade routes from one city to another, both Greek cities and elsewhere, all over the Mediterranean Sea and the Black Sea, and made a living buying and selling things. Some Greek men hired themselves out as soldiers to fight for other people around the Mediterranean, especially in West Asia and Egypt (where there is money to pay them). And, sure, ancient Greeks also often became pirates or raiders to make a living, as in the Trojan War.
Earthquakes and volcanoes
Another important thing about the Greek environment is that it is very unstable. Greece is smack-dab in the middle of a very active volcanic zone, where the Europe tectonic plate meets the Africa tectonic plate. There are several active volcanoes, and earthquakes are also very common. You get a nervous feeling that there could be a natural disaster at any time. This got the Greeks interested in a particular kind of religion which we call oracles. Oracles are the gods speaking to people, often in the form of minor earthquakes, and the gods tell the people what is going to happen in the future.
Cutting down the trees
One final observation: the Greek landscape does not look the same today as it did in the Bronze Age. There used to be quite a lot of trees on the hillsides of Greece, but people cut most of them down, and now the hills of Greece are mostly bare, or have little bushes on them. Nobody is quite sure when exactly the trees were cut down, but very likely it has to do with the beginning of using iron in Greece, around 800 BC. You have to heat iron very hot (1537 degrees Centigrade) in order to melt it, and that takes a lot of wood fires.
Greece the Land (Lands, Peoples & Cultures), by Sierra Adare (1998). Geography, climate, and more.
Ecology of the Ancient Greek World, by Robert Sallares (1991). Not easy going, even for adults, but very interesting.