You might not have time or resource to take out of your busy schedules to go to days’ worth of training, and you don’t have to. As well as more traditional training, The Charlie Waller Trust provide free online training for those working in education that look at topics from what signs you need to look out for, knowing who to involve, and transitions.
If you are able to dedicate a bit more time and money into training there is lots of training run through different charities and organisations. Mental Health First Aid provide training which can be found here.