please i need help with my first money site.

i just got a domain name and hosting for my first money site, i have installed wordpress but i dont know what to do next. i dont know how to select or install theme. please i need some one to put me through the basics, please.

Its very easy and you may just need an hour to learn and do it. There are many free WP tutorial available all over the web. I think you should go through any of them and ask specific doubts.

After installing wordpress, on the left hand panel, you can see Appearance. Hover your mouse on that, after that Appearance->Theme. Then on that top, you can see "Add new". Click on that, and then you can see all free theme listed over there. In case if you wish to upload your own theme, again click on "Upload theme" and browse the theme from its location and done

You SHOULD not use the theme which is shared for free because it takes to much risk and may lead to a local attack with those bug in the free giveaway, if possible, buying a premium clean theme which is suitable for your niche or use defaut theme
There are tons of tasks to do after installing your theme.
1. Install SEO plugin: Yoast, All-in-One seo plugin
2. Keyword research and content publishing

Watch some videos on YT. They will walk you through all the steps.

Here you go: http://www.wpbeginner.com/beginners-guide/how-to-install-a-wordpress-theme/

Since you are new to wordpress, make sure you take a look here: http://www.wpbeginner.com/beginners-guide/

It will cover all the basics.

I'd suggest you to watch some tutorials on youtube, find info, and do some research dont come to us asking questions you can find the answer on the internet.

Watch some basic installing videos in youtube