My advice is to keep your investment low and only purchase hardware/software if necessary (this actually carries over into a good rule when interviewing, most systems start small then scale based on demand and necessity). No need to break the bank here, spin up a few AWS/GCP/Azure free-tier instances for everything and go to town. Heavy competition between the leading cloud platforms means these companies are basically BEGGING you to sign up and learn their products. Take full advantage.
aws.amazon.com
cloud.google.com
azure.microsoft.com
Spend 21-days or so on networking, then 21-days on storage, then on databases, then on security. Use your spare time to really research the sectors and figure out what you like.
If you hit a point where you need to invest in hardware, hit me then sir.