It's not so much the dog doesn't listen, more that he doesn't understand what you want him to do. Go back to basics and don't punish him when he toilets indoors. Double your vigilance and take every opportunity to put him outside to toilet. The crucial thing is to be present when he does toilet in the correct place, so that you can reward him. This makes him keener to repeat the performance to get another treat. Conversely, if you have been telling him off for indoor accidents he may already feel inhibited about going to the toilet in your presence, including when he goes outdoors. This is one reason why it's important not to punish for inappropriate toileting. Can dog aggression be trained out?
Effective dog training does not require many items, but there are a few basic supplies that will help make the process more convenient and effective. Choose a dog collar or harness that is suitable and comfortable for your dog. Then decide which dog leash is best for training. A retractable leash is not appropriate for dog training. You will also need dog training treats that your dog enjoys and are easy to eat quickly so the reward is more immediate. There are plenty of great treats available at pet stores or you can also use something you make at home, like small pieces of plain cooked chicken or turkey. Can a dog wear a collar and a harness?