I am visiting as a tourist and do not have any Canadian tie
You must prove you have a genuine reason to visit Canada.
As you are married + you have children, it could seem rather unusual that you would like to holiday in Canada/visit as a tourist without your wife and/or your children. Also, the visa officer is likely to question why you would like to visit Canada (and not Europe, for example) as you don't have any host/relative/friend.
I have travelled to South Africa, Kenya, and UAE.
Unfortunately, none of these countries help as 'Travel History' for a Canada TRV.
I am a business man and own an I. T consulting firm here in Nigeria for the past 5-years.
You'll need to include evidence such as your company's business registration + that it is actively trading (work contracts/purchase orders + company bank statement + employees + office lease + audit/balance sheet, etc etc)
I am Married with 3-lovely children
You'll need to include documents such as your marriage certificate + birth certificates/copies of passports of your children and your spouse + prove that you live at the same address and they are dependent on you
You can also include proofs of any property/land owned by you, including the valuation + other financial investments + other reasons to return to Nigeria by a specific date (with evidence)