Well, yes 
all sections and the instructions are already quite terse.
From the install page, Install /e/OS on a Realme 9 Pro 5G - “oscar”, you might make an accurate copy of the headings all of which you need to be able to follow in sequence.
Reading the page the first difficulty is this:
Download the required firmware for your model.
- Realme 9 Pro 5G - 14.0.0.501(EX01)
This @Manoj seems to direct straight back to the install page.
Maybe @Mr.G you can identify, with certainty, if your phone has this firmware before you even start.
To get another insight into the install process you might read from the LineageOS wiki Install LineageOS on oscar | LineageOS Wiki. This also introduces the concept of variants of this phone – another thing to check before you start.
You asked about Downloads; you will need one whole line from the download page as:
This will give you 5 items, in the above order they are:
| e-2.9-a14-20250323478433-community-oscar.zip | [MD5 | SHA256] | recovery-IMG-e-2.9-a14-20250323478433-community-oscar.zip | [SHA256]
|The main ROM | MD5 checksum | SHA256 checksum | Recovery + , importantly in an archive.zip file, containing e-Recovery and other required secondary images, dtbo.img and boot.img | SHA256 checksum for the archive.zip
Checksums exist for one to confirm the download as received was an exact copy.
Another insight to the install process here [HOWTO] an Unified Install Guide Project for /e/.