Can't seem to run my laravel code using xampp

So I downloaded an application from bitbucket that uses the laravel framework. When I tried running:

composer update

I get an error (listed below)

In ProviderRepository.php line 208:

  Class 'Spatie\Activitylog\ActivitylogServiceProvider' not found  


Script @php artisan package:discover handling the post-autoload-dump event returned with error code 1

Then when I try viewing it on my local host (using xammp) I get another error.

Parse error: syntax error, unexpected ‘const’ (T_CONST), expecting variable (T_VARIABLE) in /Users/sandeepsuri/Prepr_Web/vendor/symfony/http-foundation/HeaderUtils.php on line 21

I'm confused as to what the problem is and I'm not too sure how to fix it.

via Chebli Mohamed