Not going to receive any tax form from robinhood - where to report the dividends earnings

You report the $10 dividend exactly where all your other dividends -- the ones you got Forms 1099 for -- get reported. If you are using a tax preparation program such as TurboTax, you will be asked to generate a 1099-DIV form even though you will not be getting one from RobinHood or from any other financial institution that paid you less than $10 in dividends. Such fake 1099-DIVs are not sent to the IRS by your tax there preparation program if you are filing electronically, any more than your paper 1099 Forms need to be attached to your paper tax return if you are filing a paper return; they are merely internal documents within the your tax preparation program that save the programmers from writing a whole bunch of code (and questions and answers) to guide the taxpayer into reporting all the dividend income in this relatively rare situation.

The IRS allows business that skip the issuing of 1099 forms if the amount is under a specific amount. You the tax payer are still required to report the income.

So I am using HR block software and I need to enter the dividends manually as I am not receiving any form from Robinhood. Let's say if I have earner $2 from company X , $3 from company Y, then 1) do I fill 1099 DIV for each company/stock separately

Your tax software, should have a help item telling you how to handle the situation where you didn't get a 1099. You should make a separate entry for each company. It will make it easier to track them from year to year. Just because you didn't get one this time doesn't mean you won't get one next time.

2. Does the dividend amount goes in to 1 a ordinary dividends section of the form.

Depends on what the dividend is. It is possible to also get a 1099 for capital gains without selling anything. Of you are unclear what goes in which box, you may have to talk to Robinhood.