A great resource for starting out is Reddit's /r/personalfinance/ community. Especially if you are managing debt and/or a negative net worth. If you don't really know how to calculate your net worth then you probably should start with the Reddit Personal Finance wiki (above) or perhaps a book like I Will Teach You To Be Rich.
The Reddit Personal Finance Wiki is an absolute no brainer.
If you only have a bank account and credit card with a single bank and pay off your card every month, you can probably just your bank's apps to track your money. When you need to do analysis, export the data as CSV and import it into Excel or Google Sheets. Once you have at least three (preferably six) months of cash reserves built up, you should absolutely switch to putting the money you are saving into a portfolio. The easiest thing is to open up an account and just buy a single fund - a total market index fund.
If you are managing debt - in particular, if you have more than one credit card and/or don't pay off your card[s] each month, I'd suggest starting out with Mint. In this scenario, your goals are to get to at least three (preferably six) months of cash reserves and wiping out your credit card debt.
If you pay off your credit cards each month and are tracking investments of any kind, I would suggest Personal Capital.
Both Mint and Personal Capital pull in your account data automatically, including automatically classifying most transactions. I usually export all of my data as a CSV file each year when I do my taxes, which is also a great chance to tweak any transaction classification if I haven't gotten around to do it earlier. You can tweak the classification of any transaction with the mobile apps. More fun and less stressful than social media!
If you are thinking about building a portfolio but are worried about trying to pick the right stocks, check out the three fund portfolio to start. In brief - just pick a few large, well diversified, low fee index funds. You can buy these index funds with just a few clicks with any online broker - most banks are partnered with one, or you can just use something like Schwab. Then, just move the money back and forth as needed.
- Test Plan vs Historic Data - very clean UI. Highly recommended.
- How Long Will Your Money Last - more options. Includes "death wedge" for maximum existential dread.
- /r/FinancialPlanning
- Engaging Data - Survive Early Retirement
- cfiresim
- FireCalc
- Monte Carlo
- Composer Very slick system for building and comparing different investing strategies.
- /r/financialindependence - Retire!
- /r/fatFIRE - Retire rich!
- /r/coastFIRE - Retire medium!
- /r/leanfire - Retire early without much money!
- /r/AskEconomics - Great for macroeconmic questions.