Hey Everyone! Great question follower!
One thing that I like to keep in mind when reading Romans, is that Paul has a way of speaking on a subject, expanding it, and then coming back to build more on the same subject. A great example is how Romans 5 spirals toward Romans 8. This is only one example why we need to take the Bible as a whole, because sometimes, the bible is like a flower that is blooming, we only need to wait as it blossoms before our eyes.
See what you think of this and how it relates to Romans 5.
Genesis 3:17-18 And unto Adam he said, Because thou hast hearkened unto the voice of thy wife, and hast eaten of the tree, of which I commanded thee, saying, Thou shalt not eat of it: cursed is the ground for thy sake; in sorrow shalt thou eat of it all the days of thy life; Thorns also and thistles shall it bring forth to thee; and thou shalt eat the herb of the field;
Romans 8:21-22 Because the creature itself also shall be delivered from the bondage of corruption into the glorious liberty of the children of God. For we know that the whole creation groaneth and travaileth in pain together until now.
The short answer to how I see it, The sin of Adam affected all of creation. No longer was humanity able to live in harmony with all of creation. As a result, for the sake of humanity, creation was cursed. Humanity was originally called to care for creation (Genesis 2:15), and through their fall, corruption occurred throughout creation. Man would learn through experience that what he put his hand to would not always produce fruit, but often, thistles and thorns would arise.
Since the fall of man, creation has been groaning in anticipation for reconciliation. Paul goes on to write;
Romans 8:23 And not only they, [All of creation] but ourselves also, which have the firstfruits of the Spirit, even we ourselves groan within ourselves, waiting for the adoption, to wit, the redemption of our body.
When the Hebrews spoke of "Firstfruits" (Leviticus 23:9-15), it was a good Jewish way of saying, "Yeah baby! There's more where that came from" :D