I have asked this question earlier , and somehow I managed with some twitter api .Now I,m going to tell you the very simple and best way to get your twitter post in your site,
Step 1: First create an twitter account then login.(if you don't have any twitter account please create first).
Step 2: on the top right corner click on your profile icon and select the settings.
step 3: At the left sidebar click on widgets,
step 4: click on create new and start configuring it.
step 5: After configuration click create widget , and you will see the textarea where the automatic code selected .
Copy and paste the code into the HTML of your site.
go for it. Thanks!