Sorc 1/Cleric 1 should be pretty solid.
You'd have 3 L1 spell slots per day, you'd get access to medium armor and Shields, which is a nice boost to your AC. You'd also pick up the first domain feature for your cleric, which can be quite good. A S1/C1 would be a solid combination, it's a bit MAD as you'd want to make sure you have wis/cha/dex, but that's not the end of the world.
Sorc 19/Cleric 1 has a bit more issues. You only have the few L1 cleric spells, and lots of Sorcerer spells, make sure you took cleric spells that scale (so you can cast them in your higher level spell slots).
You miss out on the Cleric's Channel Divinity feature, which can be quite good. More importantly though, you miss out on the Sorcerer's capstone which will limit your effectiveness at L20. The Sorc's capstone is Sorcerous restoration which restores 4 sorcery points every short or long rest. Considering the number of things you have to use those on by L20, it would be a shame to miss out on that refresh.
A more significant dip into cleric might be more beneficial. 4 levels gets you the ability score improvement you miss by not taking Sorc 19. The second level of cleric gives you channel divinity and your second divine Domain feature. So I think, personally, I'd look at a heavier investment in your second class if you are going to give up your capstone.