Summoning spells are very much real. Summonings can be commonly dangerous, as to summon something is forcefully command something to appear. Whether or not they show up depends on their power and will. Don't be fooled to think you are alone if a summoning spell appears to have failed, as it is almost certain you caught something's attention. Based on my experiences, when you try to summon a being, you are opening a door, which invites curious spirits, sometimes good, sometimes bad. I recommend you try calling otherworldly beings through much nicer methods, so you don't invoke the wrath of the entity.
Then you shouldn't be doing it and expecting it to work. You must learn magick. Study it. You can't just start with some of the harder things and expect it to work out. You have to know what magick is. How it works. Then, maybe then , you'll have better chances if it working.
depends on the spell you are using if it claims that you can bring forth something mythical into a physical body then don't trust it but if you summon forth something like a god or goddess or anything like those then yes it can work but also be aware that your ability bring forth energy among other things affect if you can summon forth this entity for your needs and wants