It depends on what server you want to play. It is not hard to download a pirated version of Minecraft and play it without paying. But, if you do it, you won't have access to most online servers available on the internet. In my opinion, the best thing to do is to buy it. After that, you can download any server you want from https://servers-minecraft.net/minecraft-bedwars-servers . Check it out by yourself. I am sure you won't be disappointed about it. Also, you can build your server here.