Shopping area and night market is concentrated around Lee Gardens area. Commercial shopping can be done at Lee Gardens, Central and Robinsons. Do visit the place at different timings as the stalls are constantly changing between timings.
For travelling, you can hail a tuk tuk anywhere you like. It cost you just 40 Baht / pax to go anywhere within Hatyai Town area. It will cost more if you were to head out of town areas.
I supposed you'll be at Hatyai during the weekends? Then you can visit the Klonghae Floating Market. It is a smaller version of BKK's, nothing much.. But you can visit just to have an experience of it.
If you're a buddhist or taoist, you can visit the Goddess of Mercy Hill to pay respect. There's also a connecting temple on the next hill that offers respect to the 4 face Buddha. I do caution you NOT to take the tuk tuk to these places as the roads on these hills are super steep. Pay a little more and get a private car or van.
Enjoy!
