HI You can't really set the timing with out it running the best you can do is set the crank to TDC move the distributor to where the rotor is pointing to #1 wire.
(Remember the crank turns twice to one turn of the distributor.. So one time the crank is at TDC it well be pointing to the #1 wire the the next time it well be pointing the other way.) I do hope you paid attention to where you marks were on the timing gears and how many times you've turned it during assembly..
That well get you close enough to get it started.. once its started set the timing to 10 -12*. then proceed to run the brake in for 25 minutes from mild idle to 2500 rpms every little bit for 25 minuets.
That will do it. But first-starts are hectic already. My 2¢ is if I am breaking-in a flat-tappet cam, then I want to set timing before I crank or start it, making start quick and painless. If you have a multi-meter, set it to continuity (squeals/beeps when there is continuity) and clip it to each side of the points (point arm and distributor body). Set the crank to 10°BTC on the #1 firing (compression) stroke. Mark where #1 cap terminal should be on the distributor body with tape or something.
With a loosened distributor clamp, rotate the distributor body mark to where the rotor is pointing. In that immediate area, you will find the spot that the meter will stop squealing. That is the ignition point. Lock the distributor down exactly at that point of squeal/no-squeal, and it's timed to exactly 10°BTC. Check and follow your cam manufacturer's instructions for break-in routine.
If it's a roller cam, have no fuel in the carb or pull your EFI fuel pump fuse and crank the engine while checking or setting timing with the light. I always pre-set timing before first-firing for a quick and smooth startup.
That will get it running, but if I don't know the distributor's exact curve, I re-time it to max total. Disconnect the vacuum advance and plug it. Rev the engine to the point you can see it does not advance any further with rpm, and set it to your engine's approximate total, such as 38° for a stock typical FE or 36° for a '60s SBF, etc. You can do this while holding rpm, or you can rev to check total (e.g., 40), idle-down, move it a little (-4) and rev to re-check (target 36). The total timing point is more important initially than your base idle timing. Reconnect your vacuum. Do more ignition tuning later to get it perfect. Hope that helps.