Is it okay to use a gasket maker instead of a gasket? No this is not going in a car it is for a lawnmower/small engines.
I made a gasket for a small single cylinder engine from a copper sheet.
Annealing and making it fit are obvious... But it worked perfectly.
Would I use "goop" - no.
Making a paper template is handy, I have had success with laying suitable brown paper on to the block or head, sticking with grease or similar, then tapping gently with a tiny hammer to break the paper over the edges...
Not for a head gasket. These are typically covered with a thin foil that resists the high temperatures of combustion or are made from a heat-resistant material. They are alo thicker that basic bulk gasket material and you could be artificially raising the compression ratio with thinner material. Get the right gasket for this. Generic gasket material or gasket maker goop is not appropriate for this.
Another problem with gasket maker goop is creating a uniform gasket surface to torque the cylinder head down on. A non-uniform gasket could distort or even crack the head once you get started torquing down the head bolts.
I have used gasket maker goop when refitting the valve cover on an OHV small engine after valve clearance adjustment. Other gaskets for intake, crankcase and even float bowl can be cut from bulk gasket material or gasket maker goop. Fifty years ago I used an x-acto knife and a hole punch to make my own from an old shoe box but time spent isn't that important to a twelve year old.