Whether you'll get pension payouts from a former employer when you retire depends on how long you held that job. The less time you spent with that employer, the smaller your payout tends to be. Moreover, your right to "keep" your traditional pension benefit is determined by your employer's vesting schedule.
Unlike 401(k)s, pensions aren't portable. You can't move a traditional pension account to your new employer or into an IRA rollover when you leave a job. (A cash-balance plan, by contrast, allows you to take your money with you when you leave a job.)
When you reach retirement age, you need to get back in touch with the folks who run the pension for your old company and apply for your benefit.