Can anyone share me a good GATK4 workflow, I Couldnt find anything good that explanins the process in a crisp and easy way.
Completly, agree - there's a real lack of clarity when it comes to documentation of some tools and options.  And it's only trolling through dozens of forum posts on any number of issues that you can begin to troubleshoot common issues.  Example workflows won't resolve those headaches but the following resources may help you get started.

 1. IBM White Paper - I found this most useful because I didn't want a .wdl cromwell workflow.  https://www.ibm.com/downloads/cas/ZJQD0QAL
 2. NIH HPC has a Good GATK4 tutorial/workflow with detailed explanations and examples I wish had been available when I made my workflow - https://hpc.nih.gov/training/gatk_tutorial/
 3. Broad github .wdl scripts -  Not ideal if you don't want to use .wdl, but they can still clarify some things.  Making them even less ideal, the Broad regularly deems these scripts as 'outdated'.  https://github.com/gatk-workflows/broad-prod-wgs-germline-snps-indels     and also https://github.com/gatk-workflows/gatk4-basic-joint-genotyping/blob/main/gatk4-basic-joint-genotyping.wdl
 4. Workflow using Nextflow for the variant calling - https://github.com/gencorefacility/variant-calling-pipeline-gatk4

