I recently rolled over my 401k into an Ira Can I also open a roth Ira?

Answer 1

If your only contribution to the traditional IRA is the rollover, then you may still be able to contribute up to $4000 ($4,500 if you are over age 50) to either the same traditional IRA or to a Roth IRA, depending on which one best fits you.
There are other factors involved here, such as whether or not you still contribute to your employer's retirement plan and how much you make. I'd be happy to do the calculations for you if you'll give me those numbers. But I understand that is sensitive information, so I will send you the link to the form you use to figure allowable contributions.
Rollovers are not considered contributions because they are in the same type of tax-advantaged plan. You would only have to be concerned if you put more into the IRA than you had in the 401K, or, conversely, if you spent some of the money and didn't out it all in (you might be liable for tax and penalties in that case).
Let me know if I can be of further assistance :)