I think the question is more about what you want to get out of your training.
Do you want to get stronger? CrossFit will get you stronger, but there are other programs that will get you stronger faster. Do you want to be physically well-rounded and be able to run, jump, lift? Then CrossFit is probably a good choice.
If you're concerned about not having enough strength, try a free CF session with scaled weights, or visit the BrandX forum and try a few scaled WODs with the lower weights, and see if it's too much for you. You could try a different program instead, like Starting Strength, and use that for 10 weeks or so before moving on to CF.
You could also just go to the gym and have a trainer spend an hour or two showing you the basic lifts and help you get established with what weight you should start each lift at, how many reps and sets to do, etc. (PS Stay away from the iso machines!) You could also do this on your own- you just need to make sure you have somebody to check/correct your form, and you cannot be afraid to start with too LITTLE weight!
What I did: I asked my husband what lifts I could be doing, and paired his suggestions with lifts I found when I simply googled "beginners weight lifting strength training". I watched lots and lots of Youtube videos to observe proper form, read descriptions of proper form, and practiced at home with a broomstick with my hubby watching. Then I went to the gym and started with the bare bar on everything- bench, squat, deadlift, press, etc. It was absurdly easy for things like squat and deadlift, so I put more weight on and watched myself like a hawk in the mirrors for each lift. As I added more weight, I would casually and nicely ask some other guy taking a break to observe and tell me if he had any pointers. I did this for 2-3 months before starting CrossFit, and it helped a lot. I now CF by myself in my globo gym and use scaled weights for all WODs- I'm going to have to join a box before I start upping the weight, but I've seen huge gains in overall physical fitness and strength even with the scaled WODs.
Sorry this is so long- and good luck! :)