I've recently purchased the game, and I am unable to find any scenarios in Standard or Free Roam. Also, I've bought certain DLCs but the game is not recognising them, it asks me to buy them again, thus, I can't even subscribe to scenarios from Workshop. I can also not find any routes apart from DLC. What might be the case ? I am super frustrated rn.
I'm not familiar with the current bundle but its likely that there are no Standard or Free Roam scenarios included which is the case with most new routes. Have they been installed yet? There can be a some time between buying DLC and the download/install actually starting although that's not always, or even usually, the case. Where are you being told to buy them again? Steam should know you've bought a DLC immediately even it if hasn't been installed.
Have a look in your Steam Client > Library the Right Click on Train Simulator > Properties then choose DLC You will have a full list of what you have purchased thru Steam for this game If anything does not a Tick next to it then it has not yet been installed Tick it to start the installation