I am really interested in learning computing, there is a program called React that is for building user interfaces.
How long has React been around?
It has been around since 2013 and aims to provide speed, simplicity, and scalability
I wish I knew more about building interfaces.  Would you recommend any other programs for a beginner?
I am just learning so for no all i know is React which allows people to create large web applications with ease. 
Where did React start up?  In the US?
Yes it was created in the US but is currently maintained by Facebook and Instagram
Is it used for smartphones too?  Or computers?
React, was announced at Facebook's React Conf in February 2015 and open-sourced in March 2015.
On April 18, 2017, Facebook announced React Fiber, a new core algorithm of React framework library for building user interfaces. React Fiber was to become the foundation of any future improvements and feature development of the React framework.
On April 19, 2017, React 360 V1.0.0 was released to the public. This allowed developers with React experience to jump into virtual reality development.
On September 26, 2017,
anyone interested in philosophy, now has 800 members in 68 countries, though it is only two years old. The society's magazine, Philosophy Pathways, goes out fortnightly to more than 1,000 addresses, and around 400 students from 40 countries have participated in its distance learning programme." In May 2014, the British philosopher and literary critic Christopher Norris sent an email to Geoffrey Klempner with the following message: "I am sending (by attachment) a poem -- actually a long verse-essay -- that you might wish to