There have been many assumed rumours about covid vaccines
Some people believe whatever rumours they hear, other people look at the data.
how it isnt safe
Look at the data.
and a means of reducing the human populations
When it's a sunny day, and you look up and say 'the sky is blue and clear', and your friend says 'no, it's green with pink spots', then it's difficult to know what to say to them.
How a person who is vaccinated later get infected with covid again even after collection of the vaccines
You need to understand how vaccination works.
many believe it too earlier and short for covid vaccines to be fully tested as effective enough,so it considered to be a trial process
Some people were saying this at the beginning. I'm not aware of anyone other than you saying this after a year and a half of vaccinations, and 12 billion doses administered worldwide. You're really stretching credibility to claim this is an early trial. The data are abundant, the proof of safety and efficacy absolutely crystal clear.
Look at the data.
My friend who has taken the vaccine got the Covid virus last month after his daughter who was not vaccinated got infected with it. Since she stayed with the family, she ended up spreading it to the rest of the family.
You ask yourself what is the need for getting the vac when you can still get traumatised with the infection.
You've given the answer yourself, above. If the daughter had been vaccinated, chances are she wouldn't have infected the family.
Vaccination isn't magic, it doesn't give people superpowers or make them invulnerable. But it does confer a high (but not 100%) degree of protection. Look at the data. Here's a chart from 2021, for example.