basically i've picked up my brothers bass that he never really got into and was wondering a few thing.

he sold his bass amp and basically i've been just using it on a shitty begginer fender amp until i get a bass beginner bass amp... i noticed bass slapping doesn't sound right, i assume the amp is the reason, right?

what would be a good beginner amp?

i only really want to learn funk bass(think rhcp, bootsy collins), would that be something i should do as soon as i begin? like, after i learn the basics funk wouldn't be hard to get into, right?

any specific techniques i should look into?

i'll be able to play funk on a squier jbass, right?
I play on Acoustic amps there really good imo. its all about what you like go to a music store and try everything out.
Left handed bass player

1998 Fender Mexico Jazz Bass

2006 Warwick 5-string Rockbass
jazzs work good for funk. funk isn't the easiest genre for a bass player but its not too terribly hard.

check the FAQs for a list of good beginner gear.
no sir away a papaya war is on
Look at Peavey's line of practice amps, the Acoustic B20, and anything you can find by Kustom (they go dirt cheap used).

As for why your slapping doesn't sound right, its a combination of using the wrong amp, and (I'm assuming) your slap technique isn't too developed yet. You'll have to practice to hone your technique, slapping isn't easy by any means.
Composite Aficionado

Spector and Markbass
Well bass thru a guitar amp just sounds crappy to begin with not to mention how it blows the speaker.

I think it will sound better after a bass amp is used but slapping is. Difficult technique and even after 5 years of doing it I still feel like there's so much room for improvement. Just practice and save up for an amp. Check out craigslist too as I found a 15 watt bass amp for 29 bucks. Was gonna get it but then found a bass for 60 haha

Guitarist for 11+ years
Bassist for 6+ years
Drummer for 5+ months

PSN account - DeadAimHeadshot
Slapping shouldn't be affected by the amp - it's more likely some mistake in technique, as slap is harder to get to sound right than fingerstyle.
Funk can be hard, but you might as well get into now, you've gotta learn at some point.