Guerilla grow on the cheap! Any advice appreciated!

First time poster and newb grower here. I'm gearing up to embark on my first whole-hearted effort at serious growing. I'll give the rundown of where I'm at and where I plan on going with it before opening up the discussion.

I've germinated my seeds and started them in a tray of small organic pots made from peat which will supposedly rot away when transferred to their permanent home. I filled the pots with organic seed starter and they are currently under the lights and have been sprouted for about 2 weeks. They range from 2'' to 6'' in height.

I plan on putting these outdoors soon. I have mixed up a soil consisting of wholesale topsoil, peat moss, vermiculite, and perlite. Since I plan to plant in an area that has a good amount of vegetation, I figure the soil is fairly decent so I would like to cut costs a little by using a 1:1 ratio of my mixed soil to the topsoil i dig up when planting. Am I crazy in my thinking here?

Ass far as nutes go I have yet to provide any and somewhat lost here. When do I need to start providing nutes, am I already off-schedule? I've heard a lot of people use jack's 20-20-20. I can't get Jack's here so I'm thinking of going with Sta-Green brand which is also 20-20-20, they also have 16-16-16.

As I said before any help would be appreciated. I'm new to this other than just throwing out a few seedlings and letting nature take its course.

C'mon guys I know someone out there can help a new grower get started and hopefully at least end up with a few decent plants to get myself through the year on. Some of my leaves are starting to turn yellow and curl. Should I go ahead and fertilize? Are they alright in the cups filled with seed starter or do I need to place them in a new medium now instead of my planned 2 weeks down the road? If fertilizer is the answer then would some random Lowe's brand 12-4-8 at least get them through until I get better fertilizer? I know these are super beginner questions and may be way off base but I learn quick, just need steered in the right direction.

Yes you can start a light 1/4 strenth fert.or less, now

Just becouse the area has lots of vegation does not mean the soil is always good , but either way 1/1 will be fine as long as you have no drainage issues

I find the 'peat pots' can become constricting before rooting away , when you transplant try to rip off small pieces of the pot to make it rot faster , just be carefull not to damage anything