theres a bunch of quests i need to do with cass yet I cant get her to come with me and theres no indication what to do to get her to come with me

I dont have 50 speech or barter and im level 28 so I need the alternative of talking her to work with me

I dont know if its because I need to find her caravan yet it doesnt show where it is

There isn't , you decided to neglect one of the games most important skills so you have to suffer for it.

I remember something about drinking her under the table. Not sure if it is to get her to join you or to sale the Caravan.

You can either do a Barter Check or Speech Check to get her to sell, forgot what the value for either is however.

[Edit]
Oops didn't read the OP careful enough I guess.

Depending on the skill in quest, you might be able to hit it with Skill Magazine, Drugs, and Clothing.

Boost your skills with magazines, drugs and equipment.

Important my ass, like convincing some old man to give me dynamite at the start of the game to beat some gangers gunna help with the fact you svck with explosives

I can udnerstand being denied content to things that arnt unique (such as a locked box filled with 1000 caps) but dening me content such as companions is stupid

And Speech is crap in the long run because once you have convinced EVERYONE i the game using it, the skill is useless while theres always a time to be good at medicine and repairing

if thats the case, lowest amount of barter/speech i need is 50 to complete, my speech and barter are both 10.

what combination of chems and clothing would boost me 40 points?

Not sure if you can hit 40. Do you have Comprehension? The one that doubles bonus from books?

Assuming your Charisma and Intelligence is low (I don't remember the stat for Barter or Speech, should be Intelligence or Charisma), Party Mentat adds +5 to Int, +2 to Chr (I think). Regular Mentate should still stack with it and it should add another 2 to the stat.

That should add around +10 points to skill (5+2*2.5-ish)

If you have comprehension, +20 from Skill magazine

+5 Speech from Pre-war business suit (for Speech)
+5 Barter from Wandering Merchant (or was it Caravan) Outfit

I think there is a hat out there (maybe it is the Caravan Hat or something) that adds +5 to Barter.

That should add more than +40 to your Barter.

There are hats that add to Perception and Charisma (not sure which though)

etc.

But it all depends on your stats being very low. If your skill related stats are already high or that you don't have comprehension perk, then you are out of luck.

Not every build is meant to solve every quest/companion in the game. You might just be out of luck and can try next play through.

If on PC there are mods that let you re-distribute your skill and stats. You can use that mod, reskill, get through the quest, and then switch back. But that just takes consequence out of your choice of character development and might/will cheapen your experience.

As for speech being a crap skill once you conviced everyone...

By then you already ended the game, so what difference does it make? Pretty sure at the final conversation there is a speech check (IIRC).

I'm sorry your hand wasn't held for your playthrough.

Seriously though, if you don't have the necessary skills, you can't access certian portions of the game. I personally don't know half the story with a few of the vaults because my first playthrough only had 19 science.

So basically your arguing it stupid they make a skill important? nice sense of logic. By denying you access to certain things the skill maintains its importance. In the long run speech is important because it comes up A LOT, by the time you have convinced everyone in the game, you've already done most everything, The out comes of many quests are affected by speech and the optimal outcome can only come from being good at it.

There is the naughty nightware +10 Speech it certainly help, but that requires a decent speech to acquire to begin with.

I was having the same problem until invested some points in to barter. Made it 30, then used trader outfit and hat, both give +5 barter. then added +10 temporary barter magazine boost and voila, she is mine for life. She is so cute and has very nice comments, give her some bad ass shotgun and she is a beast.

you need to go to talk to the head of the crimson caravan company and do some tasks for the head woman there, one of them is buying out Cass's caravan, after her caravan contract is bought out she can leave the outpost and you can convince her to go with you.

Wow you really didn't pay attention, he lacks the required barter and speech skills to do that.

Once you have convinced EVERYONE the game is OVER and its time for a new different character.