Once you purchased the theme, begin installation process:
download theme package from Downloads section of your Themeforest account;
unzip it;
open THEME IN THAT FOLDER! directory and find installable modesto.zip archive in it.
Log in your domain with freshly installed WordPress and:
1. go to Appearance>Themes;
2. On the next page, click the Add New button and then Upload Theme;
3. Choose modesto.zip and press the Install Now button;

4. Activate the theme.

5. Upon activation, a pop-up window appears offering to install required theme plugins. Hit the Begin installing plugins link to start installation.

6. Select all plugins in the list, select the Install option from the dropdown and hit Apply.

7. Upon installation hit the Return to Required Plugins installer link
8. Activate required plugins.

9. After activating all theme plugins, go back to the Dashboard. You will see the Install Compatible Extension request. Click on the Yes, Install these extensions button.

11. When done, return to the Dashboard. The theme is ready to work.