Question about using own topsoil & compost

Frankly, I think we stupidly budgeted for about a third of that cost so I'm hoping there is an alternative route.

There is.

Raised beds are specifically a workaround for horrible soil--heavy intractable clay, pure sand, rock ledge, glacial till stones. If you have any kind of ordinary dirt at all, it's generally best to work with that, improving it by adding compost, composted manures, and other goodies, rather than creating an entirely new bed on top of it from scratch.

Am I able to use what we dug up and mix that with compost & inorganic materials to achieve a good soil to start with?

Not really. Ordinary backyard dirt--topsoil--generally contains a clay component that compacts and drains poorly, hence the need for special light, loose, fast-draining potting mixes such as Mel's Mix in raised beds and other containers.

I've found several little seedlings in the topsoil that we dug up and I have no idea what they are.

99.9999999% to the vanishing point of infinity probability that they are weeds. Discard them without compunction. More will come. Discard them, too. Weeding is a part of gardening. People who don't have weeds are people who are growing houseplants in the living room.

Is this recommended to use, and would this need to be broken down more before we can mix it in?

Yes. Compost is not compost until it's no longer recognizable as the stuff that went into it. If you can still identify leaves, grass clippings, twigs, etc., it's not compost yet, and will still be a net consumer of nitrogen as it continues to break down.

we got the idea that we needed to put mesh lining to prevent moles, etc. from affecting our veggie garden. We don't have moles,

/r/gardening Thread