If you still need a partner, make sure you post on the dedicated
Quests - Heroes' and Arrav (click me)
thread, as this will help you find a partner on OSRS. I recommend that you read back through the last few posts, to see if you can contact someone to help them.
You're playing RS3, you can now complete both the Heroes' Quest and The Shield of Arrav without a partner.
For RS3, these quests no longer require a partner to complete. They can be done solo.
For best results in finding an OSRS quest partner, please use the
Quests - Heroes & Arrav
thread, or check in the official in-game chat-channel: OSRS SOA.