I looked through FAQ and it didn't say if it was ok or not to make suggestions to the general stackoverflow website so just asking here.
What is meta?
- Any Stack Exchange user can ask a question
- The community provides support, votes on ideas, and reports bugs
- Your voice helps shape the way Stack Exchange operates
I assume by suggestions you are referring to suggesting new features.
The meta.stackoverflow FAQ states that you can post questions here dealing with (umongst other things), feature requests.
So yes, you can post here on meta suggestions you may have that are relevant to Stack Overflow or even the entire Stack Exchange network.
When making a feature request or suggestion, please explain why you think this is a good idea. Saying "I think this would be cool" or "I'd find this useful" is not enough. You'll have to show how your suggestion would benefit the site and it's users as a whole.
Some tips for feature-request posts -