Help out a noob

Merlin, Musashi, Raikou and First Hassan should get additional banners later in the year, all of whom are very solid servants.

BB is an upcoming welfare servant who is exceptionally useful. Try to grab her if you can. Same with Kintoki Rider.

For 1-3 star servants, I think you have the best leveled already. Keep up with Euryale and Cu, they are very good at what they do. David and Ushiwakamaru are also very good.

Bedivere is one of the premiere boss-killing sabers, outclassing even 5-stars in terms of NP damage once his interlude comes around. His drawback is that he's difficult to get to NP5 since you can only roll him on story summon, and without being at NP5, his damage is unimpressive.

Star leveling up the Tier 1/2 3* servants and any welfares you get and really you should be fine, in the long run you will be happier rolling for servants you like, rather than for gameplay purposes especially if you are gonna be F2P and can't get all servants. Nothing in this game is so hard you can't do it without 3 star servants.

This is just my opinion, but I've come to believe that you get the most gameplay advantage for your limited free rolls by concentrating on support servants (e.g. Merlin, in a year and a half Skadi, etc.) Support servants become kinda glued to most lineups, and by having your own, you can then take whatever DPS or whatever you need from friends, including doubling up on that servant (e.g. double Merlin).

I don't include waifu/husbando considerations in my decisions, so feel free to roll for your favorites no matter what.

Ultimately I think you should save for the servants you like best.

But, if you want my opinion on those you listed I think Salter Rider is the one I would Recommend saving for.

As you probably already seen Beast (?) class servants are used as bosses on a large number singularities. These bosses usually are strong against Knight (saber, lancer, archer) classes and weak against Calvary (rider, Assassin, caster) classes. Further, two of the Calvary classes (Assassin and caster) not only have a 0.9 damage multiplier but many of the more common members of those two classes don’t tend to have much attack stats.

So, imnsho, having a strong single target rider is a huge help for new comers like you and me. They can hit beast class bosses extremely hard.

Of course, by the time rider Salter comes around you should be done with the temple of Solomon and there will be new singularities and classes like moon cancer and Foreigner around. So probably take what I suggest with a grain of salt.

Keep raising Medea Mash Cu and Hans to max. Don't roll the gacha for gameplay. F2p servants can get you through the game. Roll for who you want.

As for help, you can always add me and use my supports! :D Friend Code : 025 409 279