How to conduct an engine overall

Given, your question is a bit confusing, as I'm not clear what you mean by "conduct" an engine. There are online repair manuals available for your car, but once again you haven't given us enough information to tell you exactly where to look. There are 40 years of Mazda 323 cars, and things have changed significantly in that time, so an engine repair for a 1963 model is going to be completely different from that of a 2003 model, so knowing what year you're interested in will change our answer.

The place to start would be here, at the Lemon manuals Mazda page.

Free Service Manuals for Mazda vehicles ~ LEMON Manuals

Select the appropriate model year for your car, for example I'll pick 1991 at random. Click on the 323 folder, then in this case the appropriate engine. We'll go with the 1800cc motor, and from there you can start with the Repair and Diagnosis link.

Repair and Diagnosis — 1991 Mazda 323 L4-1800cc 1.8L OHC Service Manual ~ LEMON Manuals

Now you can go to the Repair and Diagnosis folder, and under that open the Engine folder. Follow whichever kind of repair you're interested in; here's an example of the choices available for the particular year, model and engine we've picked.

• Compression Check
• Camshaft, Lifters and Push Rods
• Cylinder Block Assembly
• Cylinder Head Assembly
• Drive Belts, Mounts, Brackets and Accessories
• Engine Lubrication
• Lamps and Indicators - Engine
• Seals and Gaskets
• Timing Components
• Tune-up and Engine Performance Checks
• Water Pump
• Service and Repair
• Specifications
• Technical Service Bulletins

If there's anything you're still looking for after this, leave a comment with your question and we'll see what else we might be able to do to help. And please, in the future give us more information than what we have so far.