Usually during kindergarten or first grade, students will start reading in the classroom. However, teachers also want to ensure that the students know what they are reading; therefore, distributing quizzes and reading comprehension tests is an important part of the curriculum.
Some of the following links will take you to worksheets. However, at the first grade level, it would be fine to use them as examinations. You could also tweek them to make them a bit more "test" like. Combine a couple of them to create a longer exam or cut out questions if you feel like there is too much included on the worksheet:
Ready made worksheets and tests are not always going to suit the unique needs of your first grade classroom. When there comes a time that you need to create your own reading comprehension test, read through these tips and techniques to help you out.
As with any type of activity, lesson, or examination in the classroom, you need to always evaluate the specific needs of your students. For example, if you teach two first grade classes, and one is much more advanced than the other one, consider coming up with two different tests so that both groups of students are challenged within their abilities.