I don’t plan staying for a long time because I can’t afford it and I would like to be able to download the Engine however I like after cancellation.
Hey short answer is yes.
if you plan on using the source code (which is given to everyone when they sub) you will need to download that before you cancel.
As you will lose access to the source but not the binary version.
Yes I will download all those source code before I cancel my subscription even though I am not experience in C++. Thanks!
Can I also download older versions before 4.3?
Not sure but Pretty sure that you can though.
Hi,
I only subscribed for 1 month. You get all the content for 1 month, you can download old versions of the engine. After your month is up, I do not believe you can download any updates or content afterwards.
To reiterate on what’s been said already; you’ll be able to download the engine and other marketplace content until the end of your subscription. Afterwards, you’ll still have access to everything that you’ve downloaded, but you won’t be able to download future updates until you reactivate your subscription. Hope that helps / clears it up! 
Edit: And yes, you can download previous engine releases prior to 4.3! Though, it’s easily the best version, so you’d likely want to work with that, anyway.
No matter I just want the engine and the source codes I’ll archive for the future even though my C++ is still noobie phase. Thanks again guys I’m definitely getting UE4 now.
If you want some C++ tutorials here -Link
See C++ on the right hand side 