How does Pact Magic and Spellcasting work when MCing

[Consensus]

I made a thread about MCing a warlock yesterday, I've decided to do it, but am confused on how it is done. I'm at warlock 2, if I went warlock 3 I would have 2 second level spells and spell slots and 3 cantrips, if I go warlock 2/sorc1 would I get 2 first level PACT slots 2 first level SPELLCASTING slots and 7 cantrips and ~6 spells known?

[Solunaris]

I made a thread about MCing a warlock yesterday, I've decided to do it, but am confused on how it is done. I'm at warlock 2, if I went warlock 3 I would have 2 second level spells and spell slots and 3 cantrips, if I go warlock 2/sorc1 would I get 2 first level PACT slots 2 first level SPELLCASTING slots and 7 cantrips and ~6 spells known?

Pact Magic is a separate entity from regular spellcasting, and as such isn't included in the rules for multi-classing as a spellcaster. If you are a 2nd level Warlock and a 1st level Sorcerer you'd have:

2 First level Spell Slots that recharge on a short rest
2 First level Spell Slots that recharge on a long rest
5 First level Spells Known, 3 of which must be from the Warlock List and 2 of which must be from the Sorcerer list
6 Cantrips Known, 4 of which must be from the Sorcerer List and 2 of which must be from the Warlock List

But, you can cast any spell you know in any of your slots, so you could use your Pact Magic slots to cast Sorcerer Spells or vice versa.

[Consensus]

But, you can cast any spell you know in any of your slots, so you could use your Pact Magic slots to cast Sorcerer Spells or vice versa.
Picking your brain again, could I once at sorc 3/lock2 could I convert pact slots into sorcery point and vise versa

[Solunaris]

Picking your brain again, could I once at sorc 3/lock2 could I convert pact slots into sorcery point and vise versa

You could convert your Spell Slots granted by the Pact Magic Feature yes.

There isn't a difference between the Spell Slots granted by the Pact Magic feature, the Spell Casting feature, or by Sorcery Points. What differs is the recovery method when the slots are expended.

Pact Magic Slots recover after a short rest, Spell Casting Slots recover after a long rest and Slots created by Sorcery Points never recover.