Its pretty easy to summon an Angel. You can just ask in your head, the angel will come, but whether it takes physical form or not really I'm not sure. They may be seen as an orb of energy or a physical form that you are comfortable with, but either way, it will come. You can cast a circle also if you like to keep negative spirits and energies out.
Also summoning a Demon, be careful. Try not to make them angry. There are several ways to summon a demon, spells, rituals, blood, if your into that. Maybe google search it. But personally I think Angels are easier to summon, and i would go with that idea.
Blessed be ~ Olwyn
Before attempting to do any "summoning", please ensure that you are well-versed on the subect. Messing around with things you have no clue about is not only a tad disrespectful but downright foolish. A simply way to communicate with an angel is through prayer, simply pick up a Catholic prayer book and you'll find many prayers to different angels.
I dunno if you can summon them. But I'm pretty sure you can connect with them. But don't expect a person with wings to appear. It doesn't work like that
I want to say something, but too gob smacked to even say it. Summoning is a skill set, and it ain't for faint hearted, and also can even cause a lot of strife. First, if you are 13 or 15. You need to study a path, learn the basics, and then learn about yourself. You cannot just dive into this. It is NOT GOOD at all. Trust me. It is Dangerous, for those who do understand, and have no knowledge. It not like a movie from Hollywood, it is a dangerous realm to go into. Learn the basics, and yourself first, learn your limits, and weaknesses first. It takes many years to learn summoning. DO NOT EVEN THINK ABOUT SUMMONING. It causes many dangerous entities to come within you or elsewhere...that is a Warning.
Begin with the basics: Meditation, visualization, energy manipulation.
Make a regular practice of it:
Daily meditation, at least once.
Visualization and energy manipulation frequently, at least. Learn to solidify mental images, other senses if you can mentally recall or even create them, and learn to absolutely believe what you visualize is true, even when you know it is not.
Read. Read a lot. Read conflicting or at least different viewpoints on magic. Incorporate something into your regular practice. I would highly recommend Modern Magic by Donald Michael Kraig, as the book leads you through a progressing practice. But read other books as well!
Know thy self. Magic happens from within, and with personal development, with testing yourself mentally, physically, intellectually, spiritually, you will become stronger.
Learn banishing until it's like a reflex.
Learn cleansing and warding.
Learn to call specific entities. What you will learn in Modern Magick will call to specific angels fairly early on.
Don't rush. Make sure you're learning, learning well, understanding thoroughly.
Eventually you will start learning about contacting entities, and how to do so.