If you are looking for triathlon coaching then you need to find a coach with experience and expertise in racing. They should also have some history of coaching already so that they know how to properly train people. It is best to find a coach with specific experience in triathlons themselves, not a coach that trains cyclists, or swimmers or runners. Depending on your fitness and experience you might want a coach that works with mostly high-performing athletes or one that trains a variety of fitness and experience levels.
What should your coach do?
First of all your coach should make sure they talk to you and know exactly what level of familiarity you are with the sport, the three events, your fitness and whether you have competed before. A triathlon is made up of cycling, swimming and running, one after the other. Not all triathlons though are the same distance, you can get sprint triathlons that are the shorter race and you can get something like Ironman triathlons which are a lot longer. How you train for a triathlon is very much dependent on what type of triathlons you want to take part in.
Your fitness level is important because then they know whether to create a training plan that also needs to build your physical fitness, or whether the focus needs to be on training in each discipline. If you have a history of endurance sports and events the kind of coaching your triathlon coach will offer is different from someone who hits the gym a couple of times a week. Your training will consider your fitness, experience and your potential. Every person will have a different starting level, a different pace to work at and a different goal.
Other factors that will impact your training
There are a lot of things that will have an impact on your training and how well your triathlon coaching goes. The energy you put into it, the time you can spend on it, and how motivated you are, these will all factor in. People who can train daily will have a different plan than those who have full-time jobs and are also parents so can only commit so much time a week. A good coach will take that into consideration when creating a schedule for you. They will not focus on just one area but have training long-term that works on all three elements. There should be short-term as well as long-term goals that are achievable. They should track your progress and make adjustments as needed. There should be a balance in the workouts so injuries are not always happening and you get time to recover from especially intense ones.
A good triathlon coach knows the sport very well and has skills and experience they can pass on. They should come up with individual training plans and build on your fitness, endurance and of course your speed over time in each of the three events.