You can get how to root android phone here.

Find best method to root android phone here.

In the event that you've searching for how to root Android, you've no doubt observed and scrutinized about "establishing" one. At some point countless Android telephones available didn't encounter their potential, and root was the appropriate response. Helpful programming was the standard, applications that you would never use ran wild and squandered information and battery life, and the experience was horrendous all around. There are many root applications for android by which we can pull for android Phones.
So you should learn How to root J7 and how to root j7 without pc.

To know about what is rooting and how to root android click on the link.

Rooting:
Steps to Root Samsung Galaxy S5

Download the CF-auto link by chain fire according to your model number their are different models available in market
Firstly you need to know how to check the model number.
Go to settings. Go to system then go to about device and you will find your model number it may be
Ex–> SM-G900H (international exynos) OR SM-G900P (sprint)
The major variants are supported you can continue with this tutorial.
This steps will not lose any data or apps which you may have installed .but this will void your warranty. There is no way to get your warranty back but if there is, I will make sure and make a tutorial on that.
There are no other methods without tripping the Knox counter.
Download the relevant ifautoroot file which is according to your model number.
Download and install kies3 make sure its not running in the background makes sure you quit it.
Right click on the CF root file click extract here option the files will get extracted.
10. By default odin3-v-3.07 exe will be there in the extracted files but if not you can individually download odin3
Now getting back to the phone go ahead turn your phone off.
Once the backlog/capacitive keys gets off press volume down centre home and power button simultaneously.
Once it comes on downloading Moe connect your phone with a pc cable
After connecting right click on Odin select run as administrator.
As long as your devices are installed properly you will get a highlighted blue light in the left corner box.
If this does not appear reboot your pc.
Click on PDA and select CF-auto root file that we just extracted
Click start.
Here it is your galaxy s5 will reboot.
You will see a red android screen.
Your phone will get restart.
Find apps and click on Super su.
Click ok.
Now you can disconnect your phone.
You can also download a root checker app from playstore to check if you have access to root or not.