LUCK. Everybody needs some! Here are a few things I've learned in my brief 69 years. While you are hard at the early grunt work, try to decide where you want to end up before you get too far. For example, HOT ROD always talks about big HP numbers. After talking to big HP car guys for the last few years, the consensus is around 500HP is about all you can use on the street. The story I heard about spinning around three times on the freeway at 80mph was just one example of what can go wrong quickly. Then there was the guy in a 2018 Camaro that spun out in the intersection while leaving a mall and the stories go on. So I can hear the comments already; to each his own, and 500 is my number.
Buying short blocks or long blocks assembled is usually better than piecing one together part by part. Basic machine shop work can add upquicklyt even if you find a "good" block. Check with a machine shop and price out some of the work a block will need, such as a dip in the hot tank, magnaflux for cracks, line hone, cylinder boring with a torque plate, and install cam bearings for starters and you still have no parts!
Bodywork is time-consumin,g and paint material costs are hard to believe these days. You can learn to weld and do your share of the bodywork, all it takes is time. I was lucky enough to find a nearby Community College that offered bodywork classes at night, which was a huge help. They got me up to speed and had a facility I didn't have.
How deep are your pockets? It's very expensive to build a car bolt by bolt. I remember spending $40 for 10 ARP 12pt 1/4" nuts for valve cover studs on a Ford small block, and that was at least 10 years ago. BTW I live 2 miles from the ocean, and the ARP hardware was the only thing that did not rust on the car or in the house. (the price we pay to live in Huntington Beach, CA). The ARP hardware is expensive and, to this day one of the additions I am most pleased about on that entire project.
Once again good luck, take your time, and do your research before you get too far in and end up making a costly mistake. Finally enjoy the journey, there is so much to learn on a job like this, and I think that's what attracts people to this hobby. Learning, conquering the significant challenges, sweat equity, pride in a job well done, and finally cruising in a sweat ride when it's done.
Personally, I went from a drag tilt to building an AutoX car. This way I have a much more street-worthy car and on weekends I can drive it on the course like I stole it for about 60 seconds at a time.