there are a number of traditions that use summoning of djinn or other beings. traditions of ritual magic are a path unto themselves and require intense dedication, preparation and practice, practice, practice. I doubt there is anyone here that would be able to teach it out of the box to you.
theres not a "recipe" that you just do "xy and z" and poof you have a djinn. the traditions that exist require work, research and proper protection. I cant stress enough how important protection is. if you don't know what youre doing, youll hurt yourself in a bad way.
Amaravail hit the nail on the head with that.
why not start with invoking more positive entities like angels and see where that takes you? theres tons of information on qabalistic traditions if that's a path you want to follow
that being said, there are also some online sources that will sell you an item that is possessed by a djinn (or a vampire or unicorn etc). some people really get into that stuff and have a collection of entities.
I don't buy into it, it seems way too fluffy to me, but there are a lot of people who do really get into it. spirited enterprises is one site that has a decent reputation for selling that sort of thing.
im not a shill, but I am trying to answer your question. some of those items cost hundreds and sometimes thousands of dollars.
but again, there is a process of bonding yourself to the entity and so forth.
like I said, I don't believe in that, but there are a lot of people who do.