how to improve the Performance ?

Same as any site.

When you have too much traffic, your site slows down.

There are many factors that go into performance. It could be high traffic but if the blog is somewhat new, then the culprit is more likely due to a large number of pics (or high res pics), pages are too big, too many ads, plugin issues, or cache issues.

Hi, I’m from Argentina.
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 491520 bytes) in /home1/tecnoedu/public_html/tecnoinclusivas/wp-admin/menu.php on line 235

How do I solve this problem?
Thanks
Silvia

Try increasing the memory available to PHP:
https://www.ads-software.com/support/topic/253495#post-1017842