Welcome! No need to apologize for a lack of knowledge, you have to start somewhere. Screws come in two types; lab screws and clinical. Some manufacturers just have only one screw for both. Labscrews are just that and are for laboratory use only; they are made of a more durable alloy that resists elongation and can be reused in the laboratory. Clinical screws are used to screw the abutment to the implant in the mouth. It is made of a softer alloy(sometimes called a gold screw) to allow a limited amount of deformation(elongation and compression) when torqued in placed. There are varying torque values among manufacturers. Once torqued it prevents movement between abutment and implant and has attained the recommended elongation limits and therefor not recommended for reuse intraorally. Manufacturers have their recommended protocol for restorative procedures, follow them. They will often let you know if you need to use a lab screw when restoring, dont be afraid to call their tech dept if you need guidance thats what they're there for. Analogs are usually sold as is , the abutments however usually include a screw whether it be lab or clinical, usually lab; make sure to check and use appropriately. You may provide the clinical screw to the doc and that may be a additional purchase and these can be expensive. I would recommend having the doc order clinical screw.
As for how often you lose them, thats totally up to you. I would recommend some type of storage system(labelled by "manufacturer" by you) to keep the parts in. Also be aware that screws have different drive heads and you'll need an assortment of drivers to accomodate them. Check out " Diamodent " for their assortment of lab drivers.