I have never taken part in an OTB tournament (Simply put, I am not FIDE rated), and I want to. But, I can't find any tournaments to play in. I am currently resident in Sudan. Is there a website where I can find all details of a tournament (location, start date, end date, requirements, etc...)?. Please do not recommend the FIDE website; I always go there and only find finished tournaments.
One of the options is Chess Results, but even though there are some future events, probably most of the listed events will be already finished tournaments (like now).
But you can try it in the future. Just search by your federation and do the tournament selection:
Another possibility is ChessMix Calendar. There seem to be a lot of events but the problem is that most of the search (almost everything) is available only for subscribers (who paid the $25/year fee).
My next try would be The Week in Chess (TWIC) calendar, althought it is not searchable at all and most of the events are located in Europe.
You might also consider giving a "Like" to some Facebook sites like Africa Chess Confederation that announce some competitions every now and then.
One other possibility is to give the Sudan Chess Federation an email, asking about any tournaments they will be hosting soon. According to this page their email is firstname.lastname@example.org.
Please do not recommend the FIDE website; I always go there and only find finished tournaments.
Despite your wish not to be directed to the FIDE website it is nevertheless the only place where all FIDE tournaments are displayed.
The rules are that FIDE rated tournaments must be registered with FIDE at least 7 days in advance. Otherwise they are not eligible for rating.
The tournaments registered with FIDE in Sudan are given here - https://ratings.fide.com/tournament_list.phtml?moder=ev_code&country=SUD
This shows that there is only one tournament registered to be played in Sudan. It is a blitz tournament starting on 17th April. Note that is in the future. It has not started. It is not a tournament which has already finished.
That there is only one FIDE rated tournament registered to be played in Sudan in the future is a reflection of the pitiful state of chess in Sudan.
For comparison take a look at the equivalent page for India - https://ratings.fide.com/tournament_list.phtml?moder=ev_code&country=IND. There are 127 registered tournaments going out as far as February 2019.
The FIDE directory gives details of each federation. Those for Sudan are here - https://ratings.fide.com/fide_directory.phtml?country=SUD&list=837.
It gives the postal address, email address and phone number for the federation. It also gives the names and contact details for President, vice president, secretary and ratings officer for the Sudan chess federation.
Note that registration of tournaments and submitting of results to FIDE are handled by the ratings officer. Try contacting him directly because he is the one person who should know what FIDE rated tournaments are taking place in Sudan.