Thanks so much for writing to us with this question. Everybody loves to know more about angels. You don't mention whether you have read any of The Urantia Book, but if you haven't, the accounts of the angels will be a joy for you.
Most people know about the guardian angels, and we all hope we have one of those...but how can we be sure? I think the answer is that we can't be sure. According to Urantia Book teachings, here are requirements that have to be met before a human being is assigned a personal guardian, and you can read about that HERE
It says, in part:
You can read all about the "Psychic Circles" HERE
113:1.6 In the ministry to so-called normal beings, seraphic assignments are made in accordance with the human attainment of the circles of intellectuality and spirituality. You start out in your mind of mortal investment in the seventh circle and journey inward in the task of self-understanding, self-conquest, and self-mastery; and circle by circle you advance until (if natural death does not terminate your career and transfer your struggles to the mansion worlds) you reach the first or inner circle of relative contact and communion with the indwelling Adjuster
113:1.8 When a mortal mind breaks through the inertia of animal legacy and attains the third circle of human intellectuality and acquired spirituality, a personal angel (in reality two) will henceforth be wholly and exclusively devoted to this ascending mortal. And thus these human souls. in addition to the ever-present and increasingly efficient indwelling Thought Adjusters, receive the undivided assistance of these personal guardians of destiny in all their efforts to finish the third circle, traverse the second, and attain the first.
If you have read these links I've given you, you can see that in order to be sure of whether you have a personal angel, you have to be able to correctly evaluate your own progress with the circles. I find that a little difficult...maybe you won't. But since the revelators devoted an entire paper to this subject, I tend to think that this personal angelic ministry is available to many...
I grew up believing, and being taught, that I had an angel, and I have really never gotten over that, even after reading The Urantia Book. I don't think there is any way to know without a doubt whether we have an angel, but I don't think there's any harm in imagining a personal angel. I like to think I have my own angel, but I am also aware that even if I don't have one of my own, I still have ample angelic watchcare and help.
Here's one more link for you— all about angels
38:2.1 Angels do not have material bodies, but they are definite and discrete beings; they are of spirit nature and origin. Though invisible to mortals, they perceive you as you are in the flesh without the aid of transformers or translators; they intellectually understand the mode of mortal life, and they share all of man’s nonsensuous emotions and sentiments. They appreciate and greatly enjoy your efforts in music, art, and real humor. They are fully cognizant of your moral struggles and spiritual difficulties. They love human beings, and only good can result from your efforts to understand and love them.
Thanks again for this interesting question. I hope my reply has been helpful. Please write back anytime!