Hi, I'm from Portugal too, I recommend you using some of this advice to get some customers:
Facebook is a excellent way to promote your job and what you do, join workout groups and post you abilities and diet or workout plans.
Creating a Instagram page is excellent too, post on your storys workout plans, you will probably get someone to follow you and ask for help.
Calling gyms to do online classes, here in portugal many gyms are hiring PT (Personal Trainers) to do online classes via Zoom or Skype, try to contact as many as you want.
You can search google for jobs, there is plenty of them.