Placing Adsense Ads

I am having trouble placing Adsense ads. I am switching from one theme to Catchbox Pro and though I have most of it figured out, I would like to place some ads in particular spots and I'm using the same plugin "Adsense Insert" as I did with the last theme, because it allows me to place the ads in particular spots. These are the two places I'm having difficult with: 1.At the top of the page and to the right of a banner I have on the left side. There is a huge blank space to the right of the banner and that's where I'd like to place and ad. 2.In the first post, at the top and to the left. Though my Adsense Insert setting should allow me to place and ad there but when an ad shows up, it seems to fall under the post and not within it or beside it. It isn't visible except the very edge of it under the post box. One other thing: How do I get rid of the search box at the top on the left side? I cannot seem to find an option to get rid of it. Any help would be appreciated.