Suggest you use TBN search function... lots of threads re pole buildings, workshop, etc..... good information spread all thru them.
Lots of options, kits, construction methods, turn-key versus u-build. Lots of experience on TBN already discussed.
U gotta do hard thinking about how much labor/tools/$ you have for the task. Time to construct is also a factor.
I recommend you design your "dream" building ... as it would be fully constructed... then begin costing it out... this helps focus on individual component costs and alternatives.
Items to not forget:
site preparation
slab, flooring
size... recommend go as large as you believe you need then add 50%, that's what I did and am not sorry. Note number of places that have multiples of sheds and outbuildings... more seems to always be better.
plumbing
insulation
electrical, both inside lighting, plugs, outside lighting
heating/cooling/fans, etc.
electrical service, wire, boxes, etc. from source to building (underground or aerial)
man doors... small versus wider... remember you will be taking things in/out
vehicle doors... drive thru? Width of equipment
interior fixtures, shelving, tables, etc.
In my case, I went with a weld up 40'X 60' metal Mueller building, 2 4' man doors, 1 3' man door, 1 14'wide roll up 14 foot high door, 1 16' wide roll up 14' high door, concrete slab, buble foil radient barrier. Slab and building were build by contractors, I'm doing the plumbing and electrical myself. 6 skylights in roof offer exceptional daylight lighting. I'd do it all the same way again.
Here's my thread on shop lights.