What will my Jupiter conjunct Descendant be like?

Actually Jupiter in the 2nd House could really be an awesome placement. It depends (as always) on how Jupiter is aspected.

Aspects tell the story of how well a planet is 'functioning.' If Jupiter has sextiles and trines from other planets then these are karmic rewards for something done especially well in a previous lifetime.

If Jupiter has conjunctions, squares, or oppositions to other planets then these are considered life lessons that you are to work on in this lifetime.

Since the 2nd House deals with ones 'worth' (and is well aspected) there would be a good chance of a favorable situation regarding money. Really the 2nd house is all about our 'self-worth' which is how we really 'feel' about ourselves.

If Jupiter is well aspected you probably have quite a good opinion of yourself. This is a good thing. Possibly if Jupiter is hard aspected (life lessons) then you might have TOO high an estimation of yourself. But overall a great placement for Jupiter.

I assume you are asking what will happen when Jupiter is transiting your 7th House as Transiting Jupiter conjunct Descendant (7th House cusp) has to do with partnerships and marriage. This again, due to the fortunate energies of Jupiter, could mean that you might meet someone and marry.

Jupiter conjunct your descendant means it would be transiting you SEVENTH house. Not your second house. Probably an expansion of your relationships. Also, look at what planets are in your seventh house. Jupiter means expansion and growth. It can also mean good luck! Good luck, I hope.