I confess that I have difficulties in understanding why you created this thread and why you are asking these questions when in a past post you posted your website:
https://rent.harconstruct.com/
looking at your site, I see that it is a site that offers exchange creation services, that is, you create exchanges, right? So what's the point of you saying this:
I'm thinking of opening a few exchangers of cryptocurrency and other electronic currencies, but I do not know how, are there such people among you who have been in this business? Can I have a word or advice?
you say you don't know how to open exchange but you create exchange or is this site not yours? but assuming the site is not yours, but you could ask that person who owns the site how to create exchange or how to open exchange. anyway to open an exchange you will need a lot of money, reputation and above all you have to be a very well known person in that market, it is already proven that anonymous and random people when they create an exchange the exchange does not have many customers and in the long term it disappears, but if you are a person who is well known on social networks ( I am talking about being known by people who use cryptocurrencies ) then when you create your exchange you will have many customers and of course if you go bankrupt you have a greater chance of ending up in prison