First establish whether you want a Free WordPress Theme, or a Paid for Theme plugin, as offered by third parties (ensure that your chosen theme is mobile-responsive).

The free WordPress themes, cover a variety of topic-specific styled websites; Blogs, Business, Food, Magazines, Music, Portfolios, Travel, Wedding.

WordPress also provides a theme search facility where one is able to look under layouts, styles, subject matter, etc.

Once you have selected your WordPress theme, whether Free or Paid for, just click the Install button.