Firstly it must be said that primarily veganism is about the animals. If you haven't got that then you may struggle because of the incessant pull of conforming to societal norms. Veganism is not per se a diet. It is is about reducing harm to animals when it is not necessary.
A major aspect of how we as humans harm animals is by eating meat, dairy, eggs & fish. So as a consequence veganism is associatied with removing these foods from your plate at each and every meal.
But in that word "removing" there is an question of what replaces the removed items. A whole food plant based diet stresses the importance of ading in whole plant foods. However when many people go vegan they start with what I call transition foods. This might be a vegan burger, possibly one bought from a fast food chain. These are brilliant at reducing harm to animals, but cannot generally be described as healthy food options. These transtion food choices help you reduce dependency on meat, dairy, fish & eggs. But they should not be seen as an endpoint.
Learning what consititutes a healthy vegan-styled diet is a life journey. A journey of fun and joy. With lots of new textures and tastes. Learning to break the rules of what goes with what. Want to try marmite (or similar) with chocolote? Go for it. One food item I have added recently is a large shredded red cabbage with vegan mayo and some mustard & spices. This has some amazing health benefits mixed with the mayo to make it more palatable allows this dish to reach a wider group of people.
One group of people who struggle are those who have pre-existing conditions. I for example have 40 years of arthritis to deal with. So there are some foods I avoid either absolutely entirely or limit to small amounts and on the other hand other foods that I eat more of, like red cabbage. Each person with pre-existing conditions would do well to research how to go vegan to take care of their specific medical conditions. That's a personal education at its heart that no-one else can do. At the end you will be responsible for your own improving health, day in day out.
The last group that struggle are those who go down difficult routes to health on a vegan lifestyle. I include specialities such as raw food approach etc in this. To succeed in speciality vegan lifestyles you need to work harder on your eductation and watch for common pitfalls including getting sufficient calories.
Otherwise you will succeed and improve day in day out. Enjoy!