my 90 days visa is expired. Is it possible for me to travel to Poland without a visa?
If you travel outside Czech to other Schengen countries before your residence permit is issued then you are taking a risk. You might be breaking the law, and If you are asked for any reason to show your documents then you will have a hard time making authorities understand your case.
A reason can be suspicion of having committed a crime or admission to a hospital due to unnatural causes requiring police attention (for example injuries caused by a car accident or assault).
In Poland, the law defines who is allowed to verify the legality of your presence in the country, and for what reason they may conduct verification. But there remains some communication gaps. Last year I was asked for documents by city guard (straż miejska) when I visited them to pay to a minor traffic violation. City guard are not permitted by law to question the legality of your status (only police, border guard, customs and certain official workers dealing with foreigners are allowed). Trying to argue with them only leads to them getting aggressive/defensive and generally uncooperative.
The confirmation of application for a residence permit (as far as I know) allows you to stay only in Czech until a residence card is issued. Read this letter again or call the place where you applied if you have doubts. If you remain in doubt then sit still and wait for your residence card.
2. What is Cel Wydania - 05,06 ,07 means ?
This refers to the reason you stated when you applied for a visa. They sometimes write 05-06-07 together to cover a broad range of work related applications.
05: work (for a period not exceeding six months over the next 12 months), based on statement of intention to perform work, registered with the labor authority.
06: Driver (international road transport)
07: Work based on documents other than those in points 5 and 6.
Here is a website with a the full list of of these reasons in Polish. Use google translate, it won't be 100% accurate but you will understand.
You will need to apply for a residence permit as soon as you arrive - which is now merged together with the work permit.