Again, study. The symbols are used with a particular system. If that is the one you want to follow, then start at the beginning. Learnung about thw goetic system will teach you its intricacies, and how those sigils are meant to be used. It is a very old system, so its books should be available online, distributed as public domain material.
Many systems will put a person through a very long learning phase before allowing them to take the first step into summoning. There are some good reasons. The first is to solidify a person's ability to concentrate. Another is that with the belief of summoning, banishing must be a very well-learned skill in order to clear the space, or send away anything unruly or unwanted.
Which brings it all back to study.