Basic On-Page WordPress Search Engine Optimization always start with Search Engine Friendly URLs.

You can set these via the Option Permalinks in your WordPress administration Panel.
But be aware that for these setting to work, you need to be on an Apache Web server that has Mod_Rewrite active and working!

If you are on a widows based hosting package, there is no way to achieve SEF URLs, and you have to settle for the standard produced by WordPress.

The easy way

The easiest way the get a good working .htaccess file is this:

WordPress Permalinks Optimal settings