Really impressed with the Opencart software and how easy it was for someone with little to no website knowledge to set up ... ie. Me

My question is, how easy is it to change the layout a little. I am a complete noob to this so it all seems a bit daunting tbh.
I have put a logo on the home page but it isn't in line with the menu bar beneath it. I need to raise the logos position and move it to the left. I used to be able to do this sort of thing in *.html by just searching for the image name in the pages code and adapting the position references but I don't really understand style sheets and php so not sure where I begin. Is there a wysiwyg editor for this sort of thing? if yes, can anyone recommend one and how do I tell which file is the one that needs altering as it doesn't seem as easy as html where the name of the page you need to alter is literally the address in the browser.
Is it relatively easy to do this or am I going to have to study up a little more on php and css to be able to suss it all. I am trying to learn as I go along but I haven't really got the basics yet so it is seeming like a pretty big learning curve.
Also, although this is a different topic, I was wondering where I adapt the wording of the default emails which are sent out to customers confirming their order etc.. I couldn't find these anywhere in the control panel.
Hope someone can help. Thanks very much

Nicky