In the Quran, “samaa" is sky (translated as “heaven” in English thus creating your confusion). Paradise is “jannah”.

Now, this “samaa" is a very wide place and it has many layers in it’s organization (67:3). Sometimes Quran talks about “Samaa” (singular= one layer) and sometimes about “Samawaat” (plural=while talking about all the layers together) . Sometimes it also talks specifically about “samaa-al-duniya” or the “sky near to the earth”. For example, the tree branches are in “samaa" (14:24), birds fly in “samaa" (16:79) and clouds floats in “samaa" (2:164). From this you can easily understand that, the territory of samaa starts from just above you and it doesn’t exclusively mean outer space as you assume!

“… to a good tree? Its root is firm and its branches are in the sky (“fi”=in, “samaai”=sky) [Quran 14:24]

Also, in your mentioned verse “samaa" (singular) is used, not the plural form (samawaat). Thus rain is coming from one layer, which is near to the earth.