Ok so i got a used one that used to be used by the fire department the engine i was told was rebuilt it has 2322.5 engine hours and 93130 miles. Got it about in 2019. So i had a small leak in the back for the back a/c. And my dumb ass drove it and it had no coolant cracked the radiator. My dad at the time thought it was something else thats part of the engine cant remember so it sat for a year then I replaced the thermostat and water pump hoping it was that nope. But thermostat was bad so no harm done. Saved up enough to get it looked at i cracked the radiator so replaced that and the fan. Now A/c worked but now it doesnt and it clicks if turned on( if I recharge it will that make it blow cold and not click?) . Took it on a road trip to Tallahassee Florida from tampa. Drove good used the cruise control alot of drive. (Recently when I stop or speed up it feels like it's lagging and two times when put key in to start it stutters a little but last time it did ALOT OF WHITE smoke came out from under the hood truck sounded like it was being choked I opened hood looked like the smoke was comeing from emission box but it started right up and drove after any thoughts could those two be connected? Like I watch my dad pull that wire to rev the engine does that ever need replacing?) Since i got it the front lights go off when I hit a bump and lately they take awhile to turn on auto also has never worked truck still has strobe and siren) also does the 2006 chevy tahoe take regular gas the 87? Im a 28 year old female have done alot of work on many cars with my dad but he passed this year so I have to figure out problems myself cant afford the shops $100 just to figure out the problem. Like October i had to get breaks and rotors was driving with no breaks lol normally I would do it with my dad but he used the air compressor tools and I couldnt even make the nut budge so took it to mavis cost me over $600 I was like holy shit and looking at the bill it was like they used the most expensive parts and the labor was wow. I wish there was a place where u bring ur parts and they have the tools and u pay to use their tools and do it urself and if u need help they will for a fee u know id use that place alot I love working on cars Id mostly need help with loosening things Im weak lol. I had a an early 2000s Santa Fe My dad had my do the power steering hose alone didnt check after we drove it we learned how weak i was that day hose flew off about 4 min into driving. But out of all the used vehicles ive had Tahoe is my fav so I want to keep her running. Any advice is welcome. Thanks for reading.