Noobie Needs Some SEO Advice

So I have this new website and I am trying to learn about SEO.

I am running each of my websites pages through a place called seocentro dot com where it supposedly analyzes a URL for SEO. This may not be the best route to go, but I guess its at least a starting point to learn about SEO.

Anyway, I have a page that I ran through this and it is telling me that "Website does not allow page caching." It also recommends that I add the following to .htaccess:
<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# HTML
ExpiresByType text/html "access plus 2 days"
</IfModule>

I also get "Website does not allow image caching." It is recommended that I add the following to .htaccess:
<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# My favicon
ExpiresByType image/x-icon "access plus 1 year"
# Images
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
ExpiresByType image/jpg "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
</IfModule>

And finally I get "Website does not allow CSS file caching." And the following is recommended to be added to .htaccess:
<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# CSS
ExpiresByType text/css "access plus 1 month"
</IfModule>

I don't really know anything about .htaccess, but I did try to incorporate all of this into an .htaccess file, but I think I screwed that up. The file looks like:

 
<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# HTML
ExpiresByType text/html "access plus 2 days"
</IfModule>

<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# My favicon
ExpiresByType image/x-icon "access plus 1 year"
# Images
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
ExpiresByType image/jpg "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
</IfModule>

<IfModule mod_expires.c>
# Enable expirations
ExpiresActive On
# CSS
ExpiresByType text/css "access plus 1 month"
</IfModule>

Code (markup):

I would appreciate it if someone who knows about .htaccess could give me some guidance about this.

Also, any suggestions as to where I can go to learn about SEO. I was hoping to find some expert advice here, but it seems that DP is not immune to scammers and bullsh#$tterse either so. I found what looked to be a couple of real promising threads on the subject, but seems that the OP either just disappeared or was scamming. So I am going to take a shot here to see if I can get some decent SEO advice.

Thanks in advance . . .

 

A .htaccess file runs on your server and tells the server how to handle certain queries.
First line in this file has to be always:
RewriteEngine On
- and mostly second line
RewriteBase /

otherwise the server can't regognize the command.