Where to continue my research-oriented studies after Bachelor's Degree in Computer Science?

The reason why you're not seeing scholarships for study at the master's level in Europe is that the master's degree is not viewed as the prerequisite for PhD study, but instead as the direct continuation of the bachelor's degree. As a result, you're expected to move on to the master's program, and usually at the same location you did your bachelor's degree. That means there really isn't a call for a lot of scholarship to fund master's study. However, it is possible to finance one's stay in a European university, as many schools offer part-time positions for master's students working in a research group for some number of hours per week.

However, in the US and several other countries, gaining admission to a PhD program is a good way to get your master's studies funded, as the funding is normally provided for the entirety of your graduate tenure, rather than just the PhD portion.

To get in to most programs in English-speaking countries, you will need to show evidence of a good scholastic record as well as good English skills, as evidenced by the IELTS or TOEFL. If those aren't in place, it's going to be very difficult for you to be competitive, and almost impossible to be competitive for a scholarship or fellowship.

This can only be answered backwards, by asking what you hope to get out of the study. You state you want a masters degree... masters are typically used to get a job in industry, and scholarships can be difficult to obtain. You will typically have to pay in order to go this route. There are some graduate programs that offer research masters (at least in engineering), but (1) I'm not sure how prevalent this is in comp sci, and (2) you'll be adding on at least a year to your degree in order for you to complete the research.

If you are looking for a masters so that you can move to industry, your best bet would probably be to look for jobs now, work a year or two, and then have your work pay for your masters. Many workplaces offer education benefits, and this can be a very nice way to further your education while not paying for the degree.

If you're looking for research, consider going the PhD route, which would open up possibilities for stipends.

There is no such thing as free lunch. If some university is offerring ou free tuition they want something from you. Mostly in the form of research. So PhD has a very high chance of getting a scholarship unlike Masters just because they know you are going to just study and not primarily do research.