About installing Unity - VapaaLassi/TAMKUnity2024 GitHub Wiki
Few notes:
The unity download page: https://unity.com/download will make you download Unity Hub. Install the latest recommended version from the "Installs"-tab in Unity Hub, currently it's likely going to be the 2022 LTS release.
Install Visual Studio (any version that the editor installation recommends)
That could help you a lot while programming.