Yes, queso fresco can be used instead of cotija. Both are similar in flavor and texture, and both offer a crumbly cheese that works well as an accompaniment for dishes like tacos or salads. The biggest difference between queso fresco and cotija is that the former is usually made from pasteurized milk and it melts more easily. This makes it perfect for use in dishes where you want a melty cheese such as enchiladas or quesadillas. However, if you'd like a stronger taste, then cotija is most likely the better choice.