First of all install virtual environment for your PC (for Windows you need to download virtualenv: check http:https://pip.readthedocs.io/en/stable/installing/#do-i-need-to-install-pip)

apt-get install python3-pip
pip3 install virtualenv

Create a folder for your virtual environment

mkdir venv
cd venv
virtualenv myvenv

Activate your virtual environment

FOR LINUX:
source myvenv/bin/activate

FOR WINDOWS:
myvenv/Scripts/activate

To install requirements for project go to the base folder which has requirements.txt in it, open terminal and type

pip install -r requirements.txt