Can a glider make a go-around?
No. A (pure) glider cannot make a go-around in the way a powered machine can. The glide path can be influenced by airbrakes, flaps,  chutes or slipping, but mostly those are for reducing your L/D, i.e., steepening the approach (you win again, gravity!).
Gaining height without updraft is only possible by converting kinetic energy (speed), and that gain is limited by the stall speed. So while you can rise a few meters when you pull up from landing airspeed, you will find yourself way too high above the runway at minimum speed and hoping for the best.
The highly enjoyable* spectacle of a low fly-by of a glider is achieved by starting with really high (unlandable) speed which is then converted into height and shortly followed by the inevitable landing**. For some older (mostly wooden) gliders, even this is not a very good idea because they combine a lower VNE with lower L/D ratios,  leaving you low and slow after pulling up from redline speeds.
In a glider, you get one chance for a smooth landing (freak thermals excluding). But a properly trained pilot gets used to this very quickly. A proper landing procedure together with brakes, flaps, etc. will bring you down safely.
*but not necessarily safe or recommended
** unless you catch a proper thermal or dynamic updraft.