All you need is a thread and a needle. You tie a knot and start at the back of the fabric. At the end of the sewing, the running stitch will appear on both sides of the fabric. You finish with a knot at the back of the fabric.
The running stich is often used for basting : this is called the running basting stick. This stitch is meant to hold pieces of fabric together before the final stitching is done with the sewing machine. They don’t have to be sewn nicely because they will be removed after the final stitching is done.
You can also use the running stitch to gather fabric. When you make two rows of base stitches, then pull the threads and you have raffles.
A litte hack:
If you want straight stitches you can draw a dotted line on your fabric with a textile marker (so that the drawings you made will disappear when washing) or if you don’t want any.