Changing margins in post edtior.

My www.ads-software.com site is chaitotalfitnessliving.com. I have been trying to get a pop-up plugin working to do a sign-up form for first time visitors to the site. I am on my third try. Tried Subscribe2 w/ReadyGraph and had a terrible time and could not get any real good support. I read some reviews that made me a bit glad it didn’t work. I deleted it. I went to popup maker and had a worse time and even less support. By this time I was truly frustrated. About two days. But five straight hours today for something that seems quite simple. I then went with “Welcome Popup”. I activated it and in about 10 minutes I had it working. At least I think it is still working. I don’t know how to test it more than once since after that it is not supposed to open any longer. And I only have so many email accounts to set up fake subscribers. The real issue though is this. Since I edited a form that is sent to unsubscribers, my editor only lets me type half way across and then the wrap around kicks in and sends me to the next line. It looks okay in my posts, as I have two sidebars. it does however make it a bit of a chore and a hassle on long posts or pages having to have them twice as long in the editor than they already are. Also I can’t seem to find out how to change from visual to text in the editor. I don’t have the toggle button that the screenshots show. If anyone can help me it would be great. Let me tell you though. Although I can program proficiently in three and a half pretty much obsolete languages, I know nothing about any of the languages used in blogging or email. i have figured out enough HTML to mess up a couple widgets trying to add some things I wanted. Actually I am just kidding, but I could have just as well messed them up as fixed them. I was just going on the logic of the code to make sense to me and guessed with the rest , all the while hoping the worse that could happen is I mess up the widget and delete it and then put new code in a new one. Sorry for so long a post, but I would want to know as much as possible if I were trying to help someone. BTW-using twenty fourteen theme