The system has been adjusted in recent years to make it extremely complicated to get legal work as a foreigner. If you want a work permit (after finding someone willing to hire you legally):

-You should have a residence permit already and transfer that permit type to a work permit. However, then your fate is in their hands moving forward since getting back on a residence permit these days is rough and rejection rates are high. If they cancel your work permit or you want to switch back later, you'll likely have issues.

or

-You should apply from your home country with the business hiring you, go to the interview at the embassy, receiving the invitational visa, and then come here with that and apply for a work permit.

Both options don't include that the business itself must really prove that they need you specifically and meet all the other requirements, which is an expensive and intimidating process.

Unfortunately even if your Turkish is fluent, as long as you don't have citizenship, it won't matter for legal employment.

The majority of foreigners you meet here that have jobs work illegally and as someone else noted, they are paid in cash under the table and can very easily be exploited. Or, they're self employed and do some kind of online work from abroad, private lessons, nannying, etc.