There is a number of details in organizing exhibitions, but starting it with any budget and canceling it without any loss if the person does not have pride is considered a positive point.
In case you did an electronic games exhibition + you do not have money, you can reserve a place and make maps to divide it and start your meetings with the stores that can reserve your corner with payment in advance to confirm the reservation. Then make discount tickets for early purchase like SR 70 instead of SR 100, to Make people buy in the fastest time.
You can make tickets, reserve the hall, audio, and everything you need with these amounts.
So, the presence of any additional one is profit. You should also consider everything equally between you and the vendors. For example, instead of buying equipment for the tournaments, you can make a deal with one of the stores to be the official sponsor at a nominal price for the reservation with 80% of the ticket amounts for it, and thus you have saved the price of the equipment with a small profit from the tournaments.