But, with not much activitiesa lot to do, there's a more free time to study a language and to find different resources and outlets to reach out to natives and other learners.

This sounds more natural in the US.

But, with not much activities to do there's a more free time to study a language and find different resources and outlets to reach out to natives and other learners.

The summer heat doesn't particularly motivate me to do anything except stay under the AC the whole timein with the AC.

What you wrote is completely fine. I've provided a suggestion in case you wanted to lessen the implication that you are suffering so much from the heat that you are stuck next to the AC and staying there. If we instead say "stay in with the AC" we can imagine that you are somewhere indoors, but next necessarily to the AC.

But, with not muchHowever, without many outdoor activities to do, there's a more free time to study a language and to find different resources and outlets to reach out to native speakers and other learners.

With your air-conditioned room you're still able to do indoor activities, so you can clarify that the heat is preventing you mainly from outdoor activities. I added another "to" in order to create a clearer division in the sentence. I would prefer to say "native speakers" instead of "natives" because the latter carries a connotation of people who are from a geographical region, while "native speakers" can be found anywhere in the world.

But, with not muchany activities to do there's a more free time to study a language, and find different resources and outlets to reach out to natives and other learners.

The summer heat doesn't particularly motivate me to do anything except stay under the AC the wholentire time.

But, with not muchany activities to do there's a more free time to study a language and find different resources and outlets to reach out to natives and other learners.