Help customizing a wordpress theme

HI,
I just bought a wordpress.org theme and I need help switching my current blog theme over to it and customizing it a bit to my liking.
I run a food and lifestyle blog and i think the current theme i have is hard to navigate and not doing me any favors with google adsense etc. Thats why i picked this theme designed specifically for food lifestyle blogs and it has ad spaces built in.


Thank you in advance

Naomi Kathreen