I've cooked on an old cheap
Chargriller for nearly 15 years now. It's sure got it's faults, but eventually you'll learn to cook around them. Here's some tips.
Keep your fire box clean, clean out the ash every time you use it. Nothing will screw up a good smoke like getting your ash level too high and choking off your air to the fire.
Right now go on
Amazon and get a Maverick ET 73 dual remote temperature probe. It will soon become your best friend. One probe is for the temperature at the cooking grate and one is for your meat.
Make sure to season the grill properly, you can find out how on the forum
I line the bottom of the actual smoker with tin foil. Sure helps with clean up.
I never grill in the smoking chamber. I know you can, but grease dripping down onto old ash makes a huge mess.
There are lots of modifications you can make to improve the smoker. You'll find there's about a 50 degree temperature difference between the hot side next to the fire box and the cooler side next to the exhaust. Ideal would be a uniform temperature. One easy mod is to go to Lowes and get an elbow for a dryer vent and lower your stack vent level to damn near cooking level. Another mod is a tuning or convection plate to help even out the temperatures. You can get as fancy as you want . Personally I just take the charcoal basket for the smoker side, the one I'm not cooking on, turn it upside down and hang it high over the fire box opening and only a couple of inches off the bottom on the exhaust side. Sounds crude but it works.
There are lots of leaks on the smoker side. A good fix is fireplace gaskets, but I do something simpler. Take a sheet of tin foil, fold in half, then half again and again until you have a fat strip. Just bend the strip over the edges and when you close the lid it will crush the foil and seal the leak.
Most importantly, this is an art not a science. You learn by asking, reading watching and making mistakes. With temps go low and slow. I put my meat on at about 280, the temps will drop and then start to come to you. Most of us smoke at 220 to 250 degrees.
I hope this helps. Let us know how it's going for you.
Bill