Welcome to the Forum 
Venture X is a decent card for travel, but it's too early for your credit profile. It probably needs 1 year of CC history for approval. Unless you see it come up on pre qualification.
Most decent cards require 6 month or 1 year minimum for approval. I would personally wait till 6th month report before apping for another card. Sure you can get bunch sub prime useless cards now, but they are not going to help you for the future. That is why many recommend AMEX, they allow you to product change and provide Soft Pull(SP) for credit limit increase CLIs therefore they can grow easy.
I put Chase and US Bank as top CC banks, however they mostly need to see some payment history with low utilization before they approve you for decent cards and they can grow with SP.
Credit Unions are great for everyday banking and loans, but not much for CCs.
I would not rush in to add card 2 or 3 now, wait till 6th month and add #2 and wait 1 year to add the 3rd+ possibly Venture X, CSP/R, US Bank AR etc.
If you have no negative reporting on your credit report, your score should be 700+ in 6 months and 750+ in one year. Now that you have discovered this site, you probably going to have many CCs in the future and would know more ways to utilize CCs to your benefit. Also get your FICO scores.
Lastly remember: Credit is a marathon, not a sprint.
