The charges are public record and accessible through the Clerk of the Court in the county where he was arrested. That office maintains all case filings including charging documents, and you can contact them by phone or in person to ask what is on the docket under his name. In many jurisdictions the court's website also has an online case search function where you can find basic case information by name or case number at no cost.
If you want a faster starting point before contacting the clerk, TruthFinder pulls from public records databases including arrest and court records and can surface charge information quickly.
On the attorney question, if your son cannot afford private counsel he has a constitutional right to a public defender. One will be appointed for him, but the timing of that appointment varies significantly depending on how backed up the public defender's office is in that jurisdiction. In busy urban courts it can take days to weeks before a PD makes first contact. In smaller jurisdictions it sometimes happens faster.
If the family is able to retain a private attorney, doing so as early as possible in the process produces better outcomes in most cases. Private counsel has more time to dedicate to each client and can begin building a defense or negotiating with prosecutors immediately rather than after a backlog clears.
In the meantime, a letter through InmateAid lets your son know you are actively working to get information and that he is not going through this alone. That reassurance matters during the uncertainty of the pre-conviction period.