There are several steps in the install.  Most you will accept the defaults.  Those requiring configuration choices are shown below.

Select "Installation" to begin.

Select "New SQL Server stand-alone installation".

Select "Database Engine Services".

Select "Named Instance" radio button and set text to "SQLExpress".

Select "NT AUTHORITY\SYSTEM" from drop-down list. Leave password field blank.

Select "Windows authentication mode", then select "Add Current User" button.  Wait while it finds the account.  When it's done, proceed with remaining defaults until completion.