I have hollow metal door frames and decided to paint the doors and get new door handles but the new strike is too small for the opening and so are the screws. What can I do? I don’t have the old strike
These will be what is needed to slip over the hole to provide threads for the screws to go into. On the website the side you see goes inside the jamb, so the flat side is on the outside. They come in different sizes, so you will need to get the right size, if not the right thread pitch to work for the screws that will hold the strike in place. The size you will most likely need will be for an 8 gauge wood screw.
This strike, most likely will fit the hole spread.
There are typically 3 types of modern strikes available. You have one, I suggest another, and a comment suggests the third one. If it was an older jamb there would be more choices, but since it is a newer looking jamb, I don't think you need to explore that option.
Your best bet is probably to either buy or make a new strike plate with the hole in the right place but with screws that fit the old screw recesses.
Alternatively put a piece of sheet metal over the old strike plate hole and either weld it in place or drive sheet metal screws to hold it in place. Cut out a hole for your new strike plate and weld or screw it to the sheet metal.
If this is an entry door and not an interior door, it is probably worth having a professional repair it as either of my suggestions may fail to keep the door closed when bumped hard, or may have too large a gap and allow lock bypass.
Line up the new strike plate to exactly where it needs to be to match the strike and tape it in place.
Measure (a) the distance between the old screw holes, (b) the distance between the top and bottom of the new strike plate main hole (I am sure there is a fancy name for that) and the top and bottom screws, (c) the width and height of the strike plate main hole and (d) the distance of the strike plate main hole edge from the edge of the door.
Go to a hardware store with all of these measurements. Bring the new strike plate with you. Find something that matches "close enough". The strike plate main hole can be a little bigger than the new strike plate's main hole, but it can't be smaller because then it won't latch properly.