You are welcome!
I have not built from scratch. I bought mine complete and fixed things. That said, I have read a fair amount on building. One that stood out as a general recommendation was this; Collect all the big hard parts (engine/trans, front and rear suspension/axles plus wheels and tires, body) and set them up on a flat floor, blocked up at ride height. Keep adjusting until it all fits and looks the way you want. Then grab some wood 2X4s and mock up a frame. It's cheap, easy to make any changes and helps to check for any issues.
If you try to just slap a bunch of parts together as you can afford them, it will probably cause fitment issues and look 'off' especially if it's your first build.
There are bunch of builds detailed here and elsewhere. Anything from a new kit assembled with typical parts to scratch builds with exotic engines. There is something to learn from each and every one of them.