I very much agree with the statements above that you don't choose the god(dess), s(he) chooses you. Sometimes this comes as a bolt from the blue, sometimes you yourself have to send out an invitation or two and see if anyone answers.
If you are drawn to Hecate, do some serious research on Hecate and the civilization she came from. Find out how she was worshiped, her myths and lore, favorite foods, colors, perfumes. People and other deities she clashes with (important!). You may be very surprised to find Hecate is not at all as she is sometimes portrayed. Meditate, invite her to a ritual with special offerings or gifts, do something that will please her. Then wait. See if she answers you in dreams, insights, strange coincidences, anything unusual. Be patient and continue your research and meditations.
Now, here's the funny thing . As often as not, you'll be answered by someone other than the deity you were seeking. Take it seriously. Someone else was "listening in" and liked what s/he saw. Then start the process again with this unexpected deity, because you'll have a getting to know you phase ahead.
Your intuition and academic research are both important. Blessings, and I hope you and your god/dess meet each other soon.
I should mention your partnership does not necessarily have to be for life. You will change as you grow and your personal deity(ies) may change. That's fine, they aren't jealous. Just keep any promises you made and continue to show respect even if you no longer work with them.
