Now move to vulnerable machines. There are two main websites for practice on vulnerable machines. Hackthebox machines and Vulnhub Machines. There are multiples infosec guys who has written blogs related to these machines for community. First thing you need to do, read blogs for 5 machine and try to understand the approach for start on these machines.
Most of the time in OSCP you will need to use a public exploit on your target to see if you can obtain a shell on it. With that exploit you may need to modify shellcode or even parts of the exploit to match with your system to obtain a connection from your target.