cali transportation

what is the best way to get around in northern cali (bay area specifically)
im 19 so i cant rent a car and i will use BART in the oakland / san fran area to meet connects but what can i use to get to a friends house in Kerman/Fresno..wish i could stay at my bros in Sacremento but too many ppl living and hotels are expensive.

Umm you will get robbed on bart.Unless you got a cop with you.Use amtrak to fresno.Dont show people money in the bay or you will probably be getting robbed or sleeping in the bay

i may drive my car out to cali..like a day trip from texas to cali.. but where in San Fran/ Bay Area is it safe to be then.. i am from Northside Houston. Garden Oaks Project robbing wont be an issue since i dont flash money nor will i have it accessible to any person especially cops + street smart (i wouldnt be heading into an area that im not familiar with especially hard parts of tha Bay)