Straight Forward Answer

Since you're talking about getting 1 lens, I suggest a zoom lens. Here are some suggestions

http://www.bhphotovideo.com/c/product/585955-GREY/Canon_CA2813535IS_EF_28_135mm_f_3_5_5_6_IS.html

http://www.bhphotovideo.com/c/product/585955-USA/Canon_CA2813535IS_EF_28_135mm_f_3_5_5_6_IS.html

http://www.bhphotovideo.com/c/product/351548-GREY/Canon_9517A002BA_EF_S_17_85mm_f_4_5_6_IS.html

http://www.bhphotovideo.com/c/product/351542-GREY/Canon_9518A002_EF_S_10_22mm_f_3_5_4_5_USM.html

Lenses will last a long time if you take care of them. And you have to be pretty negligent to trash a lens, in my opinion, hahah. So buying a decent lens now really is worth the investment, even if you are still learning.

If you want to look for more affordable lenses, any EF lens will work with your camera. If you only want one lens to deal with, a zoom lens will give you the most flexibility

I would suggest the fastest lens you can afford so you can get decent depth of field shots. Fast meaning 1.5 f stop but keep it as low as possible or you will not be able to blur the background as much as you would like to once you start figuring things out. Trust me, you will kick yourself in the butt if you go the cheap route and find out you will wind up having to purchase it anyway.

I would also recommend starting with not going with a zoom and stay with one single lens until you get the jest of what you are doing. Personally, I am very fond of the 100mm lens as it is great for portraiture photography as well. Spend wisely my friend.