Hi Volen, that's a pretty complex shape you're trying to build, it's not really a good candidate
for starting out and learning things because it has a high difficulty level with shapes melting into
each other. Often times forms that have that kind of melting quality can be easier to do in a
sub-d modeling program rather than in a CAD program, it's a much more difficult type of CAD
model. CAD modeling is strongest when most of the design is defined well by 2D profile curves
which usually isn't the case with melty type forms with complex transitions.

It looks like your main problem though is that you're trying to do too much of it all in one single form
right from the start, for example this piece here would probably need to be ignored to start with and
you'll build it later by doing a boolean with a narrower block:



- Michael