In general there are several ways to find scholarship or fund for MSc, specially for Ph.D. For Bachelor degree it's difficult to have scholarship in Portugal.
In Portugal there are two common ways to get scholarship,
1. From FCT : Every year FCT opens 'call for scholarship' for national and international students. For getting this scholarship you have to get admission to any recognized university in Portugal. You will need a research proposal along with some other important documents such as certificates of your previous degrees, a good motivation letter and recommendation from your prospective supervisor. It's better to mention that these scholarships are basically offered for PhD positions.
You can watch this video for knowing more about scholarships available in Portugal (Bangla)
You can watch this video for knowing more about scholarships available in Portugal (English)
2. Project Based Funding: Research Centres in Portuguese universities and also research lab receive funding from FCT and European union for research projects. Then coordinator of these research projects or this certain institute or lab open positions for Master's or PhD students according to the project requirement. You have to fulfil these requirements as defined in the call for the position. You may have an important interview with the Professor or Jury during the selection process. This scholarship is available most of the time in a year. So, you need to search and find the open position and apply if you fulfil all their requirements. In my experience, chances are high to get this fund, if you can convince your professor during interview and have all the proper documents ready.
For example: here
On the other hand I will give also some idea according my experience,
- You may give a formal email to a professor with you CV ( chance is low)
- You can find a research laboratory and if this lab has your desire research area then visit their career for find the open position.
- Most important: Find the open position in Linkedin. Professor or institute post their open position in linkedin frequently.
- Try to find someone who work on any lab in Portugal. If his/her has vacancy then he/she can recommend you.