This is a complex matter. There are a number of ways to immigrate to Canada. Each way has criteria that are different.  Although you may not qualify to immigrate to Canada under one category, you may qualify under another.  Ordinarily a consultation is required to determine if someone has a reasonable chance of qualifying to immigrate to Canada under one or more categories.

Lawyers are trained professionals. Typically they have attended university for a minimum of 7 years; obtained at least a law degree in addition to any other degree they have obtained; had at least one year of training called "articles"; and passed rigorous examinations to be licensed as lawyers - "called to the bar". 

Lawyers are licensed and regulated. To maintain their license they must abide by the law and by professional standards of ethics and ability. 

Lawyers are insured for negligence and fraud. If a lawyer causes you damages by negligent conduct or fails to account to you for funds places in his or her trust, insurance is available to compensate you for your loss. Insurance is mandatory for all practicing lawyers in most if not all Canadian jurisdictions.  

Generally all the forms required to immigrate to Canada are available for free from the Canadian government. If the correct forms are used and filled out with the necessary and appropriate information and are submitted to the appropriate authority with the appropriate fee, you may be successful in your application to immigrate. There are different forms applicable to the different categories of immigration applications. Which category do you qualify under?  What is the information that separates a successful application from an unsuccessful one? What if your application has special considerations that will require administrative discretion to be exercised in your favour? What if you are unsuccessful? What appeal or other procedures are available?  All of these questions require expertise that you likely do not have.  If you are serious about immigrating to Canada, hiring a professional is the right choice.