Complex sentence: Born in London, Smith trained under the Master Builder Thomas Cubitt, who was from a family of well-respected architects working in the classical style, this experience exposed Smith to an architectural practice building major landmark structures in London.
Split into simpler sentences: Born in London, Smith trained under the Master Builder Thomas Cubitt, who was from a family of well-respected architects working in the classical style. This experience exposed Smith to an architectural practice involved in building major landmark structures in London.