think about what makes you stand above the crowd and keep advertising it can take time to build a community also if you are running a server that you cant afford to run that is an issue stop now you should run the server that you can afford if it covers costs then that is a bonus
It's all about a unique niche. There are hundreds of servers that match your description, what would make a player want to join your server vs any other one? Find a unique niche that hasn't been done yet and that's your ticket to an active server.
NOTE: These are just my personal opinions, and shouldn't be used as an answer sheet.
First of all, I'd like to say that you shouldn't host a server you can't afford. This is just my personal opinion, but I think you should try to start a bit smaller so you can afford to stay open for a long time. Building up a community and a stable playerbase takes time, at least more than just two weeks. In fact, if you downgrade your server you can spend the saved money on advertisement on different websites. Keep in mind that advertisement is only a good way for people to discover your server. This does NOT guarantee a stable playerbase.
(Advertisement by spamming the IP on other servers is never a good idea. This will only hurt your server in the long run.)
And as many of the other replies here states, your server is a typical Minecraft server. You need a unique feature to your server, or something that's not easy to find in other servers. People have different prefrences, and unless you have a hub server, I recommend you focus on one prefrence-group (e.g. survival). Having good plugins and an active staff is not enough. While it's a good thing you offer many different options like /duel, that's not enough to keep people around. You need a big main attraction to make people want to stay. For example, you can hire a plugin developer (with the spare money from downgrading your server) to make a plugin that not only suits your server's theme, but is also exclusive to your server. The staff also has to know what they're doing, because an active staff is worth nothing if they can't help people. (Knowing how to do /ban is not enough).
(If you're running a minigame server, getting a good playerbase will be difficult as you need a certain ammount of players to actually begin the game.)
Server mechanics is only 50% of a good server. You also need to have good builds. For example, on a survival server it's important to have a good looking spawn build. On a hub server you need an impressive hub build, and on minigames the maps should at the very least look like it was spent some time on, and not just made in 5 minutes. Good buildings for your server is extremely important for a good first-impression. New players won't stay if the hub is just a flat area with a few portals. However, if it's a good looking hub then they might stay long ehough to discover the good features and mechanics of your server. When making builds however, don't steal it from other servers, maps or websites. Getting the permission to use it from a builder is always an option, but I recommend you either make your own or get a team of pro builders (or just one builder) to make you unique server builds, minigame maps, etc.
If your server is lagging, it might annoy players to the extent that they quit playing on your server. Remove plugins that you won't need for the long run, but without limiting the server experience.
Having a YouTube channel for your server is nice, but unless you have any useful videos about the server to upload, there's no point in having it. You also have to find a website to share these videos on, as the chances of people coming across your server YT channel are very small. If you are making videos such as trailers, etc. for your server, make sure your videos aren't laggy (that they have at least 30 fps), that the video quality is at least 720p, and no watermarks. Believe me, watermarks takes away the feeling of a proper server.
Nothing of what I've written here guarantees a big and stable playerbase. A server's popularity is defined by the players. Remember that there are a lot of new servers out there, and coincidences are what leads a server to the top. Some YouTubers could be making a shoutout, maybe a few people just decided to play on random servers and came across yours, etc. Still, following some of the tips people have told you on this post certainly wouldn't hurt your chances.