Welcome to the Hive @shubhamjain1 . If you have access to a pull-up bar you could start with hanging from the bar. Keep your shoulders engaged, so they do not touch your ears. Palms out. You are doing a 'dead-hang'
Depending on your fitness-status, try hanging for 10 seconds or longer, then give it a nice rest like half a minute or so and go again. Try to do 3-4 sets and increase the time when you are feeling good.
If it gets to boring, like 4x1 minute, get a towel and sling it over the bar and grab it with one hand and the other grabs the bar normally. Same regimen as before. Change hands, each hand on the towel = one set. You are doing an 'uneven towel hang'.
Here in a pull-up, but you'll get the idea:
After you can hang a reasonable time, like a minute with one hand gripping the towel and the other the bar, you might have guessed it, get another towel and start the process with holding on to one towel each.
You are doing a 'towel hang' and have increased the size & strength of your forearms a lot by then.
Good luck and all the best.