Theme options are they necessary

If you are developing the theme for yourself to use I don’t see any reason for adding options if you don’t want to/know how. If you are planning on distributing/selling your theme though, you might want to consider adding some options for your customers to change the settings and customize the theme.

I’d say that options are nice to have, but not necessary at all. If you are new to WordPress, learn how it works first. Then add options down the road if you feel that it would add some value for your site.