Fishing
On some weekends, you can fish in the pond of the monastery. Fish can be used as ingredients in the canteen or sold. Some quests have bait as a reward guide, perhaps this is the limiting factor rather than the activity points.
Check our Fishing guide.
Training
If you meet an instructor, you can spend one activity point to increase your proficiency levels.
Eating together
Sometimes special feasts are organised during which you can invite two people to eat with (students or teachers), which will greatly increase your relationship, their motivation and your teacher level, but it consumes one point of activity. It is also possible to cook with your own ingredients to prepare a special meal for someone, depending on their taste, at least if you have the ingredients.
Gardening
You can grow different plants and vegetables, and harvest them later. Some are used as ingredients for cooking, and flowers can be offered as gifts.
Counseling
By going to see the cathedral counsellor, you can choose to participate in a mini-game of answers to the various questions submitted by the students. At first, the identity of the person who asked the question is hidden (although you should easily recognize it through their profile and hairstyle), and you will have to choose the right answer from 3 possible choices in less than 30 seconds. In general, using common sense and a positive attitude helps to respond well, but knowing students' tastes and interests will also help. A good answer gives, among other things, points of relationship.
Choir practice
As with the meals, by going to the choir coordinator, you can choose two people with whom to participate in the religious choir. This will gain faith points, relationship points and authority points for Byleth, among others. However, this consumes one point of activity.