I wouldn't feed at this time of year, would it become a full sized tree in the garden or is it a dwarf variety?

I would plant out as its a big tree if not trimmed once a year as in 36 metres, if feeding wait till the spring too late in the year and the fertiliser will be washed out very quickly plus the tree has gone into winter mode and will be doing very little. So take your time with choosing the final spot to plant

PICEA pungens 'Glauca' is better suited to a pot as its a very slow grower and takes at least 10 years to get to 1.8m

Gg

I would try to make it into a bonsai type and search out info on the net, especially if you don't have the room to let it go full size.