I invest solely in commercial NNN (started off that way). I personally like it much better than residential as there is a lot less management overhead and leases are usually for a lot longer, plus cashflow is very predictable due to NNN nature as long as you can keep vacancies in check.
The question on whether you can start off in NNN commercial is solely a matter of your net worth and liquid investable assets. Most people don't start off in NNN because they don't have the capital. There is no way you are going to be able to finance 85% to 100% of the deal. 60-70% is more realistic. And you are not going to be able to get anything decent below $2M (500K down) and your net worth needs to be at least 1M outside of your primary residence or banks will not bother talking to you.
So really it just comes down to a significantly higher barrier of entry compared to residential. If you have the resources I would highly recommend it but if not then it's a waste of your time.