Watch every video you can, and I really like jamie wallen. I have now got the tension problems under control after watching his video. There is learning curve just give yourself a chance. Practice Practice Practice. I use red snappers for loading and now can load my quilts quick. It really does get better!!!

Coats and Clark's quilting thread? I believe that is made to be used in domestic sewing machines. Thread made for longarms needs to be stronger because they sew at higher speeds.

I tried King Tut and Signature first, and both worked pretty well -- just a little threading and occasional breaking. Then I tried Glide thread -- never any shredding or breaking. Glide is all I've used since then! Here is a link to Glide thread: http://www.bobbincentral.com/ . If you search, there were some recent threads (no pun intended! :D ) about Glide on the QB.

Here is a link to the Jamie Wallen video on setting thread tension. This video has helped a lot of quilters (including me!) get tension set right:
http://www.youtube.com/watch?v=Q1mRhcquZTM

It is going to be difficult to develop your quilting skills if you are using thread that breaks often.

that thread is not very good-we had lots of trouble with it and now only use Glide and not problems at all.I use the C&C only for piecing -otherwise I was gonna throw it away.Try a different kind of thread and see if it is better.

I always test a small section on the side off the quilt before starting. I check the top, bobbin tensions...and make sure I am happy before putting needle and thread to the top of the quilt. I would suggest doing a practice piece..try diff threads, designs..take note on what threads you liked and what worked..and what you didn't like. Ask another longarmer close to you if they would be willing to let you use a few of their diff threads to try before you buy. and above all? don't forget to breathe! (I cannot tell you how many times I cried when I 1st started on a short arm system. I was the only person in Phoenix who owned my brand system at the time..and my dealer was in Washington State! no classes..no one to call...no Quilting board. Its amazing I am still quilting on a track system!) Hang in there!

Hang in there. I got much better after about 3 quilts. I do lots for charity. No ones compains if something is not quilte perfect. Non quilters do not have a clue. I can do a twin size one prolly in 5 hours now---from the start of loading. I just quilt free from the front of the machine. I have about 5 patterns I could almost do in my sleep. I do not have a stitch regulator. I do not even have a bobbin winder.

I use Bottom Line prewound bobbins and Essential Pro Thread from Connecting threads. I can use other threads for the top but this is what I mainly use.

My machine is old---HQ16---and bought on Craigslist. It will get much better.

I have had my LA for about 2 years now, purchased during Covid, so no testing models etc. But I've never regretted my purchase! Definitely a learning curve and doodling/practicing will help develop the muscle memory you need. Check the website specific to your machine as they might have all sorts of tutorials, cheat sheets etc to help you out.
I have been using Aurifil thread (cotton) since day 1 with no dificulties at all. Perhaps lintier than poly but I clean out my bobbin case etc with every change anyway.
There is a good printout called Troubleshooting Stitch Quality Issues from Quilters Headquarters:
https://www.quiltersheadquarters.com .

Note this is a 9 year old thread that got bumped.

A "zombie" thread, lol!

I asked in another thread whether it was an issue of some sort when an older thread gets bumped into the current world?

Responded to in that thread.