"Mining" Gridcoin is essentially different than other coins. We are not wasting computing power by calculating useless hashes but rather perform scientific calculations for which we get rewarded. Negative point is, that we can't provide Mh/s or something like this, since it depends on the project you choose. There are some projects which profit from older hardware, for example the best graphics card for milkyway@home is the r9 280x which is quite some years old now.
But even if you can't or don't want to mine you can still invest and gain status as an Investor. You are getting annual 1,5% for the coins you hold and the investment price isn't that high right now, so maybe give it a try ;)