Moon&JD

Your husband can file the I-130/I-130A petitions and pay the fee for your visa.   Then he can work on getting financial support (I-1864) for a family of 4 which will be filled when you case proceeds to the NVB stage.
 
The only option for your younger son us the CRBA.

You need to provide the proof your husband was in the USA for at least 2 years past age 14 and 5 years total so his son can get a US passport. 
The visa would be denied if hes eligible for the CRBA. 
Follow the guides on this website for both your son's CRBA and your IR1 process.  Try the ezguide first in the wiki.  

Please make sure your husband reads the I-864P sponsorship info for a household of 4.  If he doesn't make enough money he will need to find a cosponsor in 6 to 10  months.

When you apply for a visa its very important you researched everything there is to know before you apply. Luckily there are very good guides on this forum, see https://www.visajourney.com/cr1-ir1-spousal-visa/. There is also tons of information on the USCIS website, https://www.uscis.gov/i-130. Read all the info first, then start filling out the forms and gathering the evidence. The guides on both websites will take you through this process step by step. When you get stuck while doing this, there's tons of people to help you here