Is Das kapital really a good start?

^(I've been a marxist for a very long time, which is ironic because I've been doing more proxy than reading theory. I've read of course but I'm not satisfied by how much I've read considering a lot of the versions I've read are either simplified or skims of marx and engels. I've been wanting to get more into theory but a book like Das kapital (which is like 888 pages) takes too much time and I don't know how I can cram it between work and uni. Other than that do you have any recommendations on theory that is considered a "must"?​​​)