How do you wire 3-way switches using only 14-2 wire when the setup is Light-Switch 1-Switch 2 Switch 1-Light-Switch 2 and Switch 1-Switch 2-Light?
You have to use 3 insulated wires beween the two switches as is shown in the circuit diagrams shown in the Related Link shown below this answer:
How to wire 3-way and 4-way switches, including wiring diagrams
If you don't have any 14-3 then, to get 3 insulated wires, you can use two lengths of 14-2 cable and just leave one wire of one pair clipped short and not connected to anything.
If you connect extra lights in parallel with the first light you will be able to switch all the lights on and off together using the same pair of switches.
You will find more information that will help you if you look at the answer to the separate Related Questions which are all shown below this answer, especially:
How do you hook-up or wire up one light with two on-off switches?
You will get even more information if you also look at the answers to that question's own Related Questions.
As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.