Yes, research as a freshman will not happen at Berkeley. You need to have some classes/knowledge under your belt for that to happen. However, try doing what I did - I worked a campus job (which are relatively easy to get - $10/hr) during my freshman year for 10 hrs/week, then applied to SURP during my first summer at Berkeley (SURP is the Summer Undergraduate Research Program, analogous to URAP but for the Summer). Since fewer students stay over the summer, SURP is much easier and most of the appointments aren't just for summer but are permanent positions. Even if you don't like your summer appointment, you can quit and have a leg up over your unexperienced sophomore colleagues.
With regard to bioengineering at UC Berkeley, if you are truly a hard worker, it is doable. I know a BioE major from Cal that is attending UCSF. I know an EECS major that graduated with a 4.0 a semester early and is now working in the Valley. These people were smart, but most importantly they worked VERY hard. If you are a pre-med in general, you will be working VERY hard so there's no free lunch whatever you decide. There are definitely some large weeder courses in the Engineering department, but once you're in I don't think it's as hard.
If you have your heart set on BioE at Berkeley, I recommend hanging out by the BioE building (Stanley Hall) when you visit (assuming you are a Cali resident, this shouldn't be too difficult). Ask the students around you what they think about it, there are many BioE pre-meds. I can tell you one thing though - Berkeley is a completely different experience than any other college you'll encounter. I absolutely loved it, and I can definitely say that 98% of the people I met also absolutely loved it. The other 2% were from SoCal and thought it was too cold or were appalled at the way people dressed 😛