Im Jr. Member now and i have no idea how to get merits for me to become Member. What to do ?
If you think your posts should be credited with a merit then have them reviewed by higher users with sendable merits (couple of threads are compiled below thanks to krish's post). More of them can be found on the Meta section. I will update here the threads where senior members are helping the new members to earn some merits for quality post.
1) https://bitcointalk.org/index.php?topic=2825523.0
Created on January 26 - will last for a week.
2) https://bitcointalk.org/index.php?topic=2828412.0
Created on January 26 - is open
3) https://bitcointalk.org/index.php?topic=2819141.0
Created on January 25 - is open
4) https://bitcointalk.org/index.php?topic=2827596.msg28975211#msg28975211
Created on January 26 - is open
Only for Full members, Sr. Members and Hero Members
5) https://bitcointalk.org/index.php?topic=2850321.msg29237739#msg29237739
6) https://bitcointalk.org/index.php?topic=2843413.0
This is my own giveaway.
More will be added if others announce.
Edited- Last updated on 31-1-2018.
1) https://bitcointalk.org/index.php?topic=2825523.0
Created on January 26 - will last for a week.
2) https://bitcointalk.org/index.php?topic=2828412.0
Created on January 26 - is open
3) https://bitcointalk.org/index.php?topic=2819141.0
Created on January 25 - is open
4) https://bitcointalk.org/index.php?topic=2827596.msg28975211#msg28975211
Created on January 26 - is open
Only for Full members, Sr. Members and Hero Members
5) https://bitcointalk.org/index.php?topic=2850321.msg29237739#msg29237739
6) https://bitcointalk.org/index.php?topic=2843413.0
This is my own giveaway.
More will be added if others announce.
Edited- Last updated on 31-1-2018.
Or you can try easier way - post in meta, i've heard that is magic place from where merits are coming 
It's not magic. Chances of getting merits in the Meta section is high because it's one of the places where threads are frequently viewed by higher/older members.