Hi there manjupraphu, and welcome to the forum.
You use the forum by subscribing to threads and it will ask you to do this if you use Tapatalk.
If you you use Tapatalk then you can like comments, send photos with your messages and send direct messages to other users.
I felt the same when I was new here but I have settled in nicely.
I will show you how to use the forum if you are on Tapatalk.
To insert photos you have taken into your messages, simply tap the painting looking thing beside the camera and then just choose a photo you would like to insert, if you aren’t using a VIP membership you can only send in one photo at a time which is a pain in the butt.
To put in a photo you wish to take, click the camera icon and then take a photo, it will ask you to confirm or deny and you can choose whatever you want with that.
To send messages to people, click into your inbox and then click the message with the plus icon and then choose what person you would like to send a message to:
To start a thread, go to the home page not the app and then click the three dots on the top right hand corner of your screen and then click new topic.
To mark something as read, click the button that has a tick.
Oh and if you use the mobile website, then you cannot post any photos or really do anything.
I think that is everything covered. Enjoy your time in the forum and I wish you a warm welcome on this forum.
Sent from my iPhone using Tapatalk