There will come a point in your training when your dog will be well trained - the exercises will be reasonably fluent and your dog will be comfortable working in a range of training situations. You're considering competition, and your instructor is encouraging you to move forward.
Time for a bit of finishing. There are dozens of behaviors that you can train to make your dog better prepared to compete. The obvious ones are envirommental generalization for the dog show atmosphere, proofing the individual exercises, and reducing the reward schedule - this post will not address these issues.
The less obvious behaviors are quite specific to the competition ring, and should be trained just like the behaviors required to complete the exercises.
Does your dog know that the ring is ALWAYS a working space? If you condition your dog to understand that entering a ring leads to work or play 100% of the time, then entering a trial ring will be a good deal easier for both of you.
Does your dog know that a person (judge) standing a few feet off to your side or in front of you signals the start of an exercise? Does your dog know that when this person asks you a question and you respond, that work is about to begin? You can communicate this by training it - set up this picture and help your dog be successful by remaining engaged and offering interesting work or attractive motivators when he succeeds.
Does your dog know that when you move around the ring to "set up" for an exercise, that the next thing that happens is work? Teach this by doing training sessions of "set-ups"; remember this is boring for most dogs so the reward schedule should be generous.
You TEACH these things; you don't take them for granted.
If you teach your dog these expectations, then you won't find yourself trying to get your dog's attention back as you walk through the ring gate, nor will your dog check out when you have to move from one exercise to another. The only thing that happens in a ring with your dog should be connection - you and your dog as a team while another person directs the start of the behaviors that you must perform.
If you have a habit of "chatting" with the judge or your instructor before you begin, you are teaching your dog to check out when you should be paying attention to your dog. Worse, if you rely on the judge to assist with YOUR ring nerves, then your dog has no support system. Next thing you know everyone is looking at the judge, including your dog!
If you do not practice moving around in your training space , then you are teaching your dog to check out when one exercise ends (without a classic reward) rather than preparing for another one. Make sure you blend the possibility of rewards with the possibility of more work. Sometimes an exercise ends with a reward. Sometimes an exercise ends with a celebration. And sometimes an exercise ends and you move to a new spot - where you reward there or simply begin the next exercise.
Good trainers prepare their dogs for more than the exercises. They prepare for competition.
This video offers a possible starting point. This is Ollie; a young German Shepherd getting ready to compete in Novice A. He knows the exercises; he can heel, recall and perform the stays with relative proficiency as long as his trainer is actively interacting with him. Now Ollie's trainer is teaching Ollie that stepping through a ring entrance always means work, play, or food is about to begin. To teach this, Darlene steps through the gates and immediately rewards. In the very beginning it doesn't matter if he is paying attention when she steps through the gates; after he's passed through those gate a few times, he'll figure it out and he'll start to volunteer attention. At that point, she should refuse to step through those gates until he offers attention - she must not ask for attention because that is putting one of his responsibilities on her. Attention is Ollie's responsibility. At this point in training, he "pulls" her through the gates by looking up at her and offering to heel.
Ollie is learning several things here. He is learning that the way to earn a treat is to offer work. He is learning that getting into rings is a good thing. He is learning that he has power; if he engages his trainer through attention then she'll respond. He is also learning that losing attention causes Darlene to back up away from the ring entrance. Who's training who here? In this case, being "worked" by your dog is a good thing.
When he shows the beginnings of understanding then we added the garbage can as a distraction. When he apppraches the can, he is pulled back and given another chance to perform correctly.
The next step would be to add signficant distractions to the ring entrace; people; tables, chairs, dogs, etc - much like a dog show. His handler will not allow him into the ring until he works his way through this "guantlet" of distractions. Soon Ollie will take responsiblity for paying attention to his trainer regardless of the distractions that he must overcome.
At this point, getting into the ring is part of the reward. It''s relatively quiet and the distractions are minimal compared to what he has to go through to get into the ring.
The final step would be substituting the opportunity to work for the cookie once he makes it into the ring. If you have trained each exercise well and with joy; this step is a natural extension of the training he already has.
Get out a couple of ring gates and give it a try!