I have seen that many people down vote those questions which are very basic or easy. Is this website only meant for asking difficult questions or can I clear my some basic doubts and problems without getting downvoted?
No. We don't have rules against easy questions. However, we do have a rule that askers are supposed to search first, and ask only if it happens that there are no answers. You may have seen a reaction to this. Basic doubts have been covered here already (and some of them could be better answered by chatting with a teacher who can, socratically, identify the pieces missing from your background and fill them in).
See this recent blog from the founder of StackExchange. Quoting a few highlights I find relevant here. Jeff Atwood speaks mostly about StackOverflow - the oldest and biggest component of the SE network, we need to port the philosophy to math (and that is where room for differences of opinions emerges):
- StackOverflow is a Wiki first.
- If SO is working like it is supposed to, 98% of programmers should get all the answers they need from reading search result pages and wouldn't need to ask or answer a single question in their entire careers. This is a good thing! Great, even! My attempt to translate this to Math is that 98% of a new users questions have already been answered. Math.SE is a bit younger than SO, so the percentage may be a bit lower, but you get the idea. Also, IM(NS)HO a new user should spend 98% of their time here searching.
- Over time, duplicates become vast landmine fields.