In most situations, a TS patch cable will suffice. A TS cable is used for unbalanced, mono signals, which is the same type of signal that flows through your guitar cable. TS stands for tip-sleeve and is specifically designed to carry a mono signal, making it ideal for the majority of guitar pedals, as they are predominantly mono as well.
While there are instances where an effects pedal may offer a stereo option, even then, you'll find separate inputs and outputs that require multiple mono TS cables. It's rare for a stereo pedal to have a single input and output jack. In such cases, TRS cables are necessary and can be used. TRS stands for tip-ring-sleeve and is designed specifically for carrying a stereo signal.
It's highly unlikely that you'll encounter a stereo pedal with a singular input/output jack unless you intentionally sought one out. If not, sticking to TS patch cables will serve you well and won't let you down!