You should always have had a contract before accepting a positon, as this is the terms agreed on between you & the employer. If these terms were not right or suitable for you, then you would not accept the position!
Then, once you have signed your contract, arrive in Doha, you will then proceed with the requirements for your RP (resident permit). If you fail any of these requirements then you will be sent back home.
Never take a job, make a move, without agreeing terms & conditions and both parties signing a contract.
Hope this helps.