Two oldest post disappeared how do I add next page not next post

I am new to using a word press and I can not figure out why my old post are disappearing. My two oldest post are not there anymore but when I go to my dashboard the post are still there and if I click view post it takes me to the post. Do I have to add next page and previous and if so where in my theme editor do I add it if I install the next page not next post plugin code.

here is my website

thank you

http://chikauwazie.com/