The lady at petsmart didn't help me out much by catching him/her by the tail feathers.
:11: I think my hand might've "accidentally" "caught" that employee on the face!
Anyways, congrats on your new bird! Obviously, he/she is going to have some human trust issues at this point, but with some love and patience you can definitely overcome those! Right now is critical in proving to your new friend that you want to be his/her friend and won't hurt him/her. One of the best methods of gaining trust with a bird is food. Calmly offering tasty treats (bits of fruit or veggies, or certain "safe" human foods) through the bars is a great way to introduce yourself to a bird in a positive way. Another is sitting near the cage and talking to the bird in a low, soft voice (perhaps read something, doesn't really matter what) every day and just get him/her used to your presence. Don't worry about him/her coming out of the cage right now. Just work on him/her getting used to you and building trust. You will be moving on to stepping up/outside cage time soon enough, but rushing that now can unintentionally break down trust.
You also need to get him/her on a routine- A sleep/wake cycle, i.e. wake up at 7am betimes at 8pm, or whatever works for you. They need a time for interaction with you (which at this point would still be while the bird is in the cage and will evolve into time outside the cage) and a time for independent play/foraging where you are not around/in the room so they do not become dependent solely on your interaction for entertainment. Well-adjusted parrots need consistency and structure in their lives, so they feel secure and know what to expect each day. It is VERY important to set a routine now that you can adhere to more or less every day.
As for the perching, try a single branch positioned just high enough he/she can reach the food/water dish and the tail doesn't touch the floor. If he/she has to get up on the branch to get to food, he/she will learn fast enough. Keeping the branch low will prevent injury in case of an accidental fall while the bird is getting used to it. A old towel on the floor will also help cushion any falls. Once the bird is confident with perching, then you can add different kinds of branches in different positions in the cage.
Most importantly-don't rush your bird. Let him/her learn on his/her own timescale. And there are a lot of very knowledgeable people on this forum, so please don't be afraid to ask questions when you have them. People want to help others learn the RIGHT steps to take so they have a happy, healthy bird!