Obtained from: Steven
Difficulty level: Easy
Reward: 300 Exp, Money
You'll be asked to locate Maggie, and when you do it, you have to tell her and others where Steven is #1. Maggie can be found in the Lighthouse (1), sitting on a mattress in a room corner #2. After short conversation with her you can return to Steven (2) and tell him where Maggie is. You'll get a reward from him.
It is definitely best to complete some quests from a main plot first, so you can get to the Lifeguard Tower and then to the Lighthouse. If you're lucky you can even get a car to move faster and safer between these places. If you do this, Steven can be already found in the Lifeguard Tower and you can use Fast Travel to quickly move there and inform the man about Maggie.
On the Air
Obtained from: Dominic
Difficulty level: Medium
Reward: 1000 Exp, Money
Go to the lighthouse and bring back a signal amplifier
Dominic stands next to the entrance to the main deck #1. He will complain about too weak antenna, which is not able to send signals outside the island. Your task is to get a signal amplifier. It is good to complete the Lazarus Rising quest first, so you can get and access to the car and quickly reach the Lighthouse (1). Go to the top of it (if it is your first visit there you will be escorted by Colin and another quest will start automatically) and talk to James #2.
In order to get an access to the storage you have to complete the Knockin' on Heaven's Door first. After that talk to Darvin #1, who will open the storage door for you. There is a signal amplifier on one of shelves inside #2. Use Fast Travel and return to the Lifeguard Tower. Give Dominic an amplifier and obtain your reward.