How to adjust posts formats

I need some formatting down to the posts on the home page here:

https://feminomics.com/salWP/

I’ve SLpost installed and am using that on the home page which is set to static, but i cant figure out how to do these following changes.
I need the thumbnail centered.
I need the title a couple of sizes smaller, centered and not bumped up to the picture. these are basic design editing but i do not know css style sheets and whatnot so i dont know where to go to fix them.

ideally i would like it as close to this original design as possible seen here:

https://feminomics.com/salWP/wp-content/uploads/2012/12/Fem_Originallayout.png

and as a bonus, if you’re feeling like an over achiever, I would also like to know how to bump the logo flower on the right sidebar down so it rests on the footer.
Thats it. thanks

I’m using the theme: mantra
I’m using the plugin: SLPost lite