I too have just started as a secondary SENCo (April 2020, mid lockdown). My LSAs are touching base with EHCP students, carrying out welfare calls and following a rota to offer online support to students for two hours a day.
They have also completed the NEU/Nasen training webinars on planning/delivering/reflecting upon quality intervention. The videos are online, there are four and last on average 16 minutes each. I asked them to complete a reflection for each and write a target for their own practice if possible based upon the theme of the clip. I have used these to inform future training and get a better idea of the different roles.
Hope this helps.