In my limited experience with a similar service, they will send you leads and even make offers but you still need to do your due diligence and make sure it's a profitable deal for you.

If not, what will you suggest me to do?

A hands-off garage conversion ADU is over $100, even doing much of the work yourself, it will be much more expensive than your estimate.Single ADU additions in single family zoned areas are typically one of the worse re investments. 

Is the question Do I ask my parents to look elsewhere because I want to make money?

You also may need to do some work yourself, again depending on your funds.

While doing that, you should research places that are good for investing.

If you are working as a sub for me , you are interviewed , background checked , proof of insurance , license , EIN number etc .Sure hiring a illegal from a parking lot can be cheaper ..............Until they are not , they get hurt and file a claim against you , they screw up the job and it cost more to do it over than do it right .

Unfortunately, with the number of pivots that are publicized and at inexperienced investor’s disposal, there’s never been more avenues for inexperienced investors to hold on too long.I hope inexperienced investors are mindful of this because I am constantly interacting with investors who are falling for these traps and doing immense harm to themselves, even if they may not be fully aware at the time of their decisions.It's crucial for investors, especially those just starting out, to recognize that not every investment will pan out as hoped (unlike what the gurus will tell you).

our market is in Columbus Ohio and we are currently doing infill as a strategy. single family home by right can be built on any infill lot in columbus but for multifamily this strategy becomes part of entitlements and rezoning. 

When you say 'legal one family', do you mean that it is zoned for single family residential?