The Southern Poverty Law Center has collected and published a tremendously useful set of resources for people locked up by ICE and Border Patrol, and people advocating for them.
The site contains links to a webinar, a parole guide, and other resources. You can find it here: https://www.splcenter.org/ICEParoleToolkit?fbclid=IwAR1THMmsU_stiZif1PeKHvf_O01f9vB3H4hf8lzlMUwEV6F3D0LX0cgo2CA (resources are included in both English and Spanish).
The Immigration Advocates Network website offers related support, including online training materials for training to become a DOJ-accredited advocate for asylum seekers and others in the immigration system, a status for non-attorneys that offers them access to sensitive information and standing to represent asylum-seekers and people at risk of deportation. Their training resources are here: https://www.immigrationadvocates.org/calendar/
The Catholic Legal Immigration Network offers resources that go even deeper, many targeted to attorneys new to immigration work, and others that are suitable to a wider audience. Their training resources are here: https://cliniclegal.org/training