Ditto redial on the howlers! If you are new at calling, best learn to crawl and then walk before you try running pards.
Easiest call to learn to use and get to at least sound something like what it is suppose to early on is an enclosed reed type distress call. Even a few sour notes will slip by OK most times, but it is real easy to learn to use if you know what it is that it is suppose to sound like. Buy some good tapes to listen to.
Next up will be to learn and master the open reed distress calls - way more versatile when you get them down, and some also make good intermediate howlers.
Then think about learning to howl, all the different sounds and when and when not to use them.
Trying to "learn" while in a hunting situation in the field is doing little more than educating the predators and giving you a sore butt.
And with all of the above, practice a lot, remember that less is better, and don't give up - you'll eventually get it.
As for not having any success as a new comer, pretty good bet is your trying to call them in areas not holding coyotes in the first place (scouting), or picking your sets poorly, or not playing "rock" well enough.
If all of the above is just to much for you to go alone... then see if you can find a local gent with experience who will give you some help.
Great sport, but you have to do the homework to be good at it.
HTH,
Ladobe