24GB is a ton of memory. A server like that can serve quite a lot of traffic with sufficient CPU muscle behind it. Since you're not paying a lot it's fine to use a server that's waaaay overkill for your needs. However, where I would be hesitant to use your server is that it's dedicated hardware. Obviously dedicated hardware isn't problematic if you're a good server administrator and can resolve both software and hardware issues yourself. At $25 a month I'd be surprised if that included any management by your hosting provider but if it does that's an obvious bonus. You'll get better performance from dedicated hardware generally speaking but the trade off of doing your own devops makes the choice less appealing. Also, a single dedicated server doesn't provide any redundancy.
For apps that have a high amount of traffic (thousands of daily visitors), two or three mid size (4GB) VPS machines at either Linode or Digital Ocean will be sufficient. You can balance traffic between the machines. You now have server redundancy and no longer need to worry about fixing broken hardware. Essentially you're horizontally scaling your infrastructure as opposed to vertically scaling with this 24GB machine. For a truly "high traffic" app spending around $100 to $200 a month for hosting is just the cost of doing business. Some companies spend quite a bit more than that. If your app is just launching with a small user base start off with two small size (1GB) VPS machines. One machine can serve the app while the other hosts the database. This configuration is pretty cheap at $20 a month. Then, as your app grows in daily usage spin up newer larger VPS instances and balance traffic between them.