Step 1. Have an SRS pilot train you for like 10 minutes
Step 2. Just before getting into titans, have some situation occur where you and your pilot must go into battle
Step 3. Have your mentor die in action while in his titan, preferably from elite mercenaries
Step 4. In his final moments, have him link his titan to you
Step 5. Enter the titan and somehow know how to do everything despite having no training and this is your first time entering one
Step 6. CONGRATULATIONS!!!!!!
Step 7. Embark on a mission to stop this weird electric glowing ball from being placed into this really really big gun that can blow up planets while also killing every single elite mercenary and destabilizing the IMC on typhon
Step 8. Have your titan die while the entire planet explodes. Yes, it will be a small sacrifice but a necessary one until you may be linked to a new one.
Credits to: Jack Cooper for helping me with right this tutorial

(Bonus: If they're trying to corner you, you need to move, don't let them pin you down)