Your LMB & BG are adults and way, way too big to have been grown in your pond from fingerlings because the pond was completed and filled in Dec 2022.. Your feeder spring/stream to me sounds to be too small and shallow to have produced those LMB-BG. I suspect someone stocked those fish for you. Since it is now July there is almost a 100% chance reproduction of both has occurred if you have at least one pair of LMB and BG. Thus the pond is now infected with lots of small LMB - BG after spawning with little benefit to catching out the original mistake fish. It will be difficult to manage this mainly as a YP pond. However you can still have YP as a bonus fish. Often when I get a pond with just LMB and the owner wants YP they can just try to remove all the LMB they can catch and the YP population does really well. The problem in your case is you strongly need numerous LMB to control prolific BG so they do not overpopulate and stunt.
Once you verify that spawning of LMB and BG has occurred and you still want numerous nice size YP, I would remove every LMB larger than 9"-10". This skews the bass population to toward high numbers of small bass eating basically small fish of both BG & YP. IMO the bass will prefer YP to BG because YP are easier to swallow whole compared to BG. Thus for a better YP pond you will have to focus your management efforts on manually removing small BG using traps and a seine that is preferably 50 - 100ft long. Look into using Z traps and clover leaf traps - homemade or purchased - YouTube. If diligent in annually removing BG,, the pond should produce some decent sized YP. However you might have to stock several 5"-7" YP so they are not bass food to keep the YP population large enough to frequently catch 10"-12" YP. If you buy YP I would always try to buy YP that are pellet trained as it is a good investment because they grow pretty fast when you feed them.
IMO this is a good place to get minnow seines.
https://douglasnets.net/product-category/minnow-seines/I think the minnow in the picture is a dace. Common to cool water streams. Very doubtful it will reproduce in the pond - stream yes, pond very unlikely
We are very interested in the progress of your pond. Please keep us updated about your pond management efforts and success.
