According to the race creation rules, a small creature's movement speed would be 30 feet. Small creatures do not inherently get a penalty to movement and base speed is considered Normal RP (0) 30 feet. Gnomes and Halflings only have a speed of 20 feet because they are affected by the Slow RP (-1) template which reduces a creature's movement speed by 10 feet.
https://www.d20pfsrd.com/gamemastering/other-rules/creating-new-races/#TOC- Base-Speed-Quality
