Hubspot has a really good sales CRM, its free and will always be free, also another which again is free is SugarCRM you have to install it on a cloud server you could use like Amazon Web Services it is free for a year. I actually use both SugarCRM isnt really updating the free version anymore and maybe a bit more than you need, and you'll have to find someone to install it for you, Hubspot is cloud based nothing to install and a bit easier though not as robust as what you'd find with SugarCRM though for your purposes you may not need everything with Sugar. I've used Zoho in the past and it kind of sucks in my personal opinion, Sales Force is super expensive. There are quite a bit more out there though I can only comment on the ones I've used. These are better than using a spread sheet as you can setup tasks to call cusotmers in the future, take notes on projects, take notes on customer calls, you can use sub categories like cases for clients you have done or will do multiple projects for so your notes section isnt cluttered and again the best part about both of these is they are free...
"I got no game it's just some bitches understand my story." Nas