how to add next and previous post

Hi there,

Try activating the post navigation in the customizer:
https://docs.generatepress.com/article/blog-content-layout/#single

Let me know if this helps :)

i have activated the post navigation, but i will like to move the "next post" to the opposite position which is the right but it should on the next paragraph towards the right so it doesnt overlap on smaller screens like mobile

Can you try adding this first?
https://docs.generatepress.com/article/inline-post-navigation/

Let me know :)

thanks for that it fixed it, but i will like to add some space between the post tags and the next & previous post. its seem too close and i almost confused one for the other

Try this:

.tags-links {
    margin-bottom: 20px;
}