Even crochet stitches take practice. Tension is about how yarn feeds through your fingers and how each loop is formed, not about pulling as tightly as you can.
Start with comfortable hands
Choose a relaxed way to hold the yarn. If your fingers hurt, stop and rest. Tightening your grip is not a shortcut to cleaner stitches.
Make a small test piece
Crochet a few rows with the same yarn and hook. Look at the size of the loops and whether you can comfortably insert the hook into each stitch.
Try a different hook only after testing
If your stitches are consistently too tight or too loose, a slightly different hook size can change the feel of the fabric. It is still important to compare gauge when a pattern requires a particular finished size.
Watch the first chain
The foundation chain is often tighter than the rows that follow. Keep the loop on your hook comfortable and avoid tugging hard after every chain.
Practise in short sessions
Five to ten minutes of slow, attentive practice can be more useful than a long session of fighting stiff yarn.
Check your progress
Take a photograph of your first swatch and compare it with a new one a week later. Look for more consistent loop height rather than perfect symmetry.