Hello @Avin and welcome to our community!
There is an overview about this topic on the website of BAMF (German language):
http://www.bamf.de/DE/Willkommen/DeutschLernen/Integrationskurse/TeilnahmeKosten/Aufenthaltstitel_nach/aufenthaltstitel_nach-node.html;jsessionid=C357902EA63A4E4376528AB3C120E297.2_cid359
I will provide a brief summary of the most important points here:
You don't have to pay for the course as long as you get Arbeitslosengeld II (ALG II), that's correct. But you can still fill in a form to apply for assupmtion of costs if you are struggling to pay the costs due to your personal or economical situation even if you are not getting ALG II. But of course they will take into account how much your husband earns to decide whether you have to pay for the course yourself or if they will still do it.
Concerning day-care for your child:
In Germany you've got a right to get a spot for your child in a day-care center if it is between 1-3 years old. But you have to pay part of the costs. This includes 1) a certain amount that depends on your income and other factors plus 2) a fixed monthly amount of 23€. Fortunately the variable part of your payment (the first one mentioned above) is going to be omitted by 01.08.2017.
If your commune is not able to provide such a spot in a day-care center they can give you alternative options like a Tagesmutter. This might cost more than a day-care center, but the commune has to compensate extra costs.
Keep in mind that there is usually more demand than supply when it comes to day-care centers. That's why I'd highly recommend to start searching for a spot as soon as possible because it might take a while. Yet still I wish you good luck on your search!
Sources (both German language):
https://www.berlin.de/sen/jugend/familie-und-kinder/kindertagesbetreuung/kostenbeteiligung/
https://www.tagesmutter.com/rechtsanspruch-auf-kita-oder-tagesmutter-platz/
I hope this answer was helpful to you. Feel free to ask further questions if necessary!
Best regards,
Thorgen