FWIW here are my two recommendations:
There will always be shortages of one thing or another at times and part of me wants to just buy normally so as not to fuel the panic but the other part doesn't want to be the sucker that ends up with nothing, so a couple of years ago a got a big plastic box, put it in the garage and slowly filled it with tins and dried food that I knew I could make meals from and some evaporated milk. I've got some meals in tins such as soups, others I can make such as chickpeas, rice, spinach and tinned tomatoes I know I can add a few spices and make a curry. I have to confess though, I didn't prepare for the bogroll shortage!
As for seeds, last year when the shops went empty I got a trial 6 month subscription to one of the garden magazines that comes with seeds, I now have enough seeds to last me the decade! Bit short on the high value seeds mind, such as beans and peans so this year I'm stopping picking one of my bean plants early so that I can store a few seeds.
Stay safe x